W3C

Requirements for Japanese Text Layout

W3C Working Group Note 3 April 2012

This version:
http://www.w3.org/TR/2012/NOTE-jlreq-20120403/
Latest version:
http://www.w3.org/TR/jlreq/
Previous version:
http://www.w3.org/TR/2011/WD-jlreq-20111129/
Editors (first edition):
Yasuhiro Anan (阿南 康宏), Microsoft
Hiroyuki Chiba (千葉 弘幸), Invited Expert
Junsaburo Edamoto (枝本 順三郎), Invited Expert
Richard Ishida, W3C
Keiichiro Ishino (石野 恵一郎), Antenna House
Tatsuo Kobayashi (小林 龍生), JustSystems
Toshi Kobayashi (小林 敏), Invited Expert
Kenzou Onozawa (小野澤 賢三), Invited Expert
Felix Sasaki, University of Applied Sciences Potsdam
Editors (second edition):
Hiroyuki Chiba (千葉 弘幸), Invited Expert
Junsaburo Edamoto (枝本 順三郎), Invited Expert
Richard Ishida, W3C
Keiichiro Ishino (石野 恵一郎), Antenna House
Seiichi Kato (加藤 誠一), Microsoft
Tatsuo Kobayashi (小林 龍生), Invited Expert
Toshi Kobayashi (小林 敏), Invited Expert
Kenzou Onozawa (小野澤 賢三), Invited Expert
Felix Sasaki, DFKI GmbH
Hajime Shiozawa (塩澤 元), Invited Expert

A Japanese version of this document is also available. See also translations. The English version of this document is the authoritative version.


Abstract

This document describes requirements for general Japanese layout realized with technologies like CSS, SVG and XSL-FO. The document is mainly based on a standard for Japanese layout, JIS X 4051, however, it also addresses areas which are not covered by JIS X 4051. This second version of the document contains a significant amount of additional information related to hanmen design, such as handling headings, placement of illustrations and tables, handling of notes and reference marks, etc.

Status of this Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current W3C publications and the latest revision of this technical report can be found in the W3C technical reports index at http://www.w3.org/TR/.

This is a second version of a document that describes requirements for general Japanese layout realized with technologies like CSS, SVG, XSL-FO and eBook standards. The document is mainly based on a standard for Japanese layout, JIS X 4051, however, it also addresses areas which are not covered by JIS X 4051. This second version of the document contains a significant amount of additional information related to hanmen design, such as handling headings, placement of illustrations and tables, handling of notes and reference marks, etc.

This document was developed by participants in the Japanese Layout Task Force, with input from four W3C Working Groups, CSS, Internationalization Core, SVG and XSL.

The document was originally authored in Japanese, then translated to English under the guidance of the Japanese authors. In order to reach the largest international audience, the W3C works in English, so this English version of the document is the authoritative version. However, the Japanese version of this document is also available.

Feedback about the content of this document can be sent to public-i18n-cjk@w3.org. Use "[JLReq]" in the subject line of your email, followed by a brief subject. The archive for this list is public.

Publication as a Working Group Note does not imply endorsement by the W3C Membership. This document may be updated, replaced or obsoleted by other documents at any time. Therefore, quotes or references to specific information in the document should include the publication date of this version, 03 April 2012. It is inappropriate to cite this document as other than a Working Group Note, which is not an endorsed W3C Recommendation.

This document was produced by groups operating under the 5 February 2004 W3C Patent Policy. W3C maintains a public list of disclosures for each group: CSS Working Group disclosures, i18n Core Working Group disclosures, SVG Working Group disclosures, and XSL Working Group disclosures. Those pages also include instructions for disclosing a patent. An individual who has actual knowledge of a patent which the individual believes contains Essential Claim(s) must disclose the information in accordance with section 6 of the W3C Patent Policy.


Table of Contents


1 Introduction


1.1 Purpose of This Document

Each cultural community has its own language, script and writing system. In that sense, the transfer of each writing system into cyberspace is a task with very high importance for information and communication technology.

As one of the basic work items of this task force, this document describes issues of text composition in the Japanese writing system. The goal of the task force is not to propose actual solutions but describe important issues as basic information for actual implementations.

1.2 How This Document was Created

This document was created by the W3C Japanese Layout Task Force. The Task Force has discussed many issues and harmonized the requirements from user communities and solutions from technological experts. It includes the following participants:

  1. Japanese text composition experts (The editors of "JIS X 4051 : Formatting rules for Japanese documents").

  2. Internationalization and standardization experts in Japan (from Microsoft, Antenna House, JustSystems).

  3. Members of the W3C CSS, SVG, XSL and i18n Core, Working Groups.

This task force also constitutes an important innovation due to its bilingual work-flow. Discussion is mainly conducted in Japanese, because of the Japanese composition issues, but minutes and one mailing list were in English. To support development, the task force held face-to-face meetings with participating Working Groups.

The document itself was also developed bilingually, and is published bilingually. We carefully avoided using jargon for technical terms. Even if there were English words corresponding to the Japanese, we carefully studied any potential differences in the nuances of meaning, and if there were differences between corresponding concepts, we provided the Japanese jargon in romaji (Latin transliteration) for future discussion. Moreover, we prepared as many figures as possible, with clear and understandable English, to help non-Japanese readers.

1.3 Basic Principles for Development of This Document

Japanese composition exhibits several differences from Western composition. Major differences include:

  1. The use of not only horizontal writing mode but also vertical writing mode.

  2. In principle, all character frames of ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters used in Japanese composition are designed in a square box, and these characters are composed without intervening spaces (i.e. set solid). In this document, notations such as ideographic (cl-19) and hiragana (cl-15) characters indicate character classes (see 3.9 About Character Classes).

This document mainly explains the characteristics of Japanese composition along the lines of the following policy.

  1. It does not fully cover all issues of the Japanese composition system, but mainly discusses the differences from Western composition systems.

  2. It focuses on the requirements for the Japanese visual presentation form of text composition. Technology-specific interpretations of the requirements and/or how to implement them are out of scope for this document.

  3. It explicitly refers to JIS X 4051 "Formatting rules for Japanese documents" as much as possible. This document focuses on fundamental and important issues of Japanese layout as much as possible, and for more detail references the corresponding clause of JIS X 4051. The JIS X 4051 topics that are not described in this document, are only for exceptional, corner cases or to provide some specific line composition algorithms. On the other hand, some topics that are not described in JIS X 4051 are described in detail. Accordingly, this document is sufficient to implement Japanese layout processing for most parts of the Japanese market.

    In accordance with the stated policy, this document provides tutorial- or summary-like, supplementary explanations, related background, and additional descriptions for JIS X 4051 information. This document covers all the fundamental issues of Japanese text layout, but the reader will need to refer to JIS X 4051 for advanced discussion of exceptional topics.

  4. It provides typical examples of actual use for key composition features, to enable better understanding of their usage.

  5. For non-Japanese readers, frequency of use is indicated for each requirement. These frequencies are not the outcome of any accurate research, but arise from the long experience of the authors. They are intuitive for ordinary Japanese text readers; however, for non-Japanese readers it may be difficult to imagine without explicit information. These frequencies are only rough information to prioritize the importance of issues. A couple of examples:

    "warichu (inline cutting note) is not frequently used, but is useful to simply annotate persons, things, and so on, at the place where the text appears, especially in classic texts or translations.", or "ruby is frequently used in modern documents, including newspapers."

  6. In consideration of non-Japanese readers of this document, figures are used for explanations wherever possible.

  7. Text layout rules and recommendations for readable design are different things, however these two issues are difficult to discuss independently. In this document, these two aspects are carefully separated. The aesthetic design recommendations are mainly described using notes.

  8. The main target of this document is common books. The authors' experiences are mainly related to common books, and the quality required for common books is the highest in the market. There are many kinds of books in the market, and the requirements are quite diverse. The task force has a lot of accumulated experience in requirements and solutions for Japanese text composition. Nonetheless, many issues, which have been discussed over a long period of time, are applicable for other kinds of publication.

    In terms of frequency of use, the importance of magazines, technical manuals, and Web documents rates alongside common books. However, there are several characteristics in these publications, which are different from common books. These issues should be treated more fully in future documents.

1.4 The Structure of This Document

This document consists of four parts:

1 Introduction

2 Basics of Japanese Composition

3 Line Composition

4 Positioning of Headings, Notes, Illustrations, Tables and Paragraphs

2 Basics of Japanese Composition explains the characteristics of letters and symbols which are used in Japanese composition, their differences in vertical writing mode and horizontal writing mode, and the design and adaptation of the kihon-hanmen.

3 Line Composition explains line composition methods for ideographic (cl-19), hiragana (cl-15), katakana (cl-16) characters and punctuation marks, together with ruby (inter-line pronunciation information and annotation) and Japanese and Western mixed text composition, i.e. mixtures of Japanese characters and Western characters (cl-27).

4 Positioning of Headings, Notes, Illustrations, Tables and Paragraphs describes construction methods and composition methods for headings, notes, illustrations and tables.

In principle, characters in Japanese composition are designed in a square box and positioned without spaces, i.e. solid setting. This is taken as a basic premise for the design of the kihon-hanmen, the basis of book layout. Furthermore, to understand Japanese layout, it is important to understand the design of the kihon-hanmen and how to position illustrations, characters, symbols etc. in relation to it. Hence, 2 Basics of Japanese Composition describes in detail the design of the kihon-hanmen and its dependencies. In particular, 2.5 Page wise Arrangement of Kihon-hanmen Elements provides prototypical patterns for the three guidelines listed after this paragraph: what recommendations need to be strictly taken into account, and what exceptions are possible. (The goal of these explanations is an understanding of Japanese composition. Since detailed explanations of the various elements of the kihon-hanmen are given in 3 Line Composition and 4 Positioning of Headings, Notes, Illustrations, Tables and Paragraphs, some explanations are repeated.)

  1. Keep to the basic size and column numbers of multi-column format that were decided upon in setting up the kihon-hanmen, with some exceptions.

  2. Keep to the line positions that were decided upon in setting up the kihon-hanmen, with some exceptions.

  3. Keep to the letter positions that were decided upon in setting up the kihon-hanmen, with some exceptions.

1.5 Reference of Definition and Others

The definitions of technical terms are described in the Appendix G Terminology appendix. Terms are linked to corresponding places in the Terminology appendix only at first appearance and in important places. If there is no appropriate English terminology for Japanese terminology, or the English terminology may possibly cause misunderstanding, the Japanese terminology is only transliterated to Hepburn style romaji notation (except that "m", not "n", is used before "b", "m" and "p").

Also, the definitions of terminology in the Terminology appendix are basically the same as the definitions of JIS X 8125 or JIS X 4051, with respect to common Japanese usage of terminology.

Each character class has its own character class number in parentheses. Members of each character class are listed in Appendix A Character Classes, except for CJK Ideographs. Each character in this document is named and referred to using the character names of ISO/IEC 10646 (UCS).

The formal title of the frequently mentioned Japanese Industrial Standard JIS X 4051 is as follows:

JIS X 4051 : 2004 Formatting rules for Japanese documents

JIS X 4051 is available from the Japan Standards Association (http://www.jsa.or.jp/), but a PDF version is not available from JSA. The PDF version is accessible from the Japanese Industrial Standards Committee site (http://www.jisc.go.jp/), however it is not possible to download it.

2 Basics of Japanese Composition


2.1 Characters and the Principles of Setting them for Japanese Composition

2.1.1 Characters Used for Japanese Composition

Japanese letters used for composing Japanese text mainly consist of ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters (see Fig. 2.1).

Kanji, hiragana and katakana.
Fig. 2.1: Kanji, hiragana and katakana.

(note 1)

In addition to ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters, various punctuation marks (see Fig. 2.2) as well as Western characters (cl-27), such as European numerals, Latin letters and/or Greek letters, may be used in Japanese text. In this document these characters are classified into character classes, for which explanations are given describing their behavior in type-setting.

Examples of punctuation marks.
Fig. 2.2: Examples of punctuation marks.

(note 2)

The details of character classes used in this document will be explained in 3.9 About Character Classes, as well as in Appendix A Character Classes. Also, in "Spacing between Characters" all non-Kanji characters included in ISO/IEC 10646 (UCS) Annex A collection 285 (Basic Japanese character set) and collection 286 (Extended non-Kanji character set) are explicitly classified by character class.

2.1.2 Kanji, Hiragana and Katakana

Ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters are the same size, and have square character frames of equal dimensions. Aligned with the vertical and horizontal center of the character frame, there is a smaller box called the letter face, which contains the actual symbol. Character size is measured by the size of the character frame (see Fig. 2.3). "Character advance" is a term used to describe the advance width of the character frame of a character. By definition, it is equal to the "width" of a character in horizontal writing mode, whereas it is the height of a character in vertical writing mode (see Fig. 2.3).

The size of kanji and hiragana, and the character frames.
Fig. 2.3: The size of kanji and hiragana, and the character frames.

(note 1)

In vertical writing mode, the letter face of small kana (cl-11) characters (ぁぃぅァィゥ etc.) is placed at the vertical center and to the right of the horizontal center of the character frame; in horizontal writing mode, it is placed at the horizontal center and below the vertical center (see Fig. 2.4). Also there are punctuation marks with letter faces that are not placed at the vertical and horizontal center of the character frame.

Small kana and the position of their letter face in the character frame.
Fig. 2.4: Small kana and the position of their letter face in the character frame.

2.1.3 Principles of Arrangement of Kanji and Kana Characters

In principle, when composing a line with ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters no extra space appears between their character frame. This is called solid setting (see Fig. 2.5).

Example of solid setting in horizontal writing mode.
Fig. 2.5: Example of solid setting in horizontal writing mode.

(note 1)

In the letterpress printing era ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters were designed so that they were easy to read in solid setting, regardless of text direction. However, unlike the letterpress printing era, when several sizes of the original pattern of a letter were required to create matrices, in today's digital era the same original pattern is used for any size simply by enlargement or reduction. Because of this, it might be necessary to adjust the inter-character space when composing lines at large character sizes. When composing lines at small character sizes, hinting data is used to ensure that the width of the strokes that make up a character look correct.

(note 2)

Depending on the context, there are several setting methods used in addition to solid setting, as shown below.

  1. Fixed inter-character spacing: Text set with a fixed size space between each character frame (see Fig. 2.6).

    Examples of fixed inter-character spacing in horizontal writing mode.
    Fig. 2.6: Examples of fixed inter-character spacing in horizontal writing mode.

    Fixed inter-character spacing is used in books for the following cases: (Fixed inter-character spacing, including also even tsumegumi, is defined in JIS X 4051, sec. 4.18.1 b.)

    1. To achieve a balance between running heads with few and with many characters. Fixed inter-character spacing is used for the running heads with few characters. Examples of fixed inter-character spacing for running heads are given in JIS X 4051, annex 5.

    2. To achieve a balance between headings with few and with many characters. Fixed inter-character spacing is used for the headings with few characters. Examples of fixed inter-character spacing for headings are given in JIS X 4051, annex 6.

    3. For captions of illustrations and tables, which only have a few characters. Fixed inter-character spacing is used to balance with the size of the illustration or table.

    4. In some cases, fixed inter-character spacing is used for Chinese and Japanese poetry where one line has only a few characters.

  2. Even inter-character spacing: Text set with equal inter-character spacing between characters on a given line, so that each line is aligned to the same line head and line end (see Fig. 2.7).

    Example of even inter-character space setting in horizontal writing mode.
    Fig. 2.7: Example of even inter-character space setting in horizontal writing mode.

    Even inter-character space setting is used in books for unifying the length of table headings with Japanese text (see Fig. 2.8). There are also examples (e.g. lists of names) in which parts of a person names receive inter-character spacing. (Even inter-character spacing, including processing of jidori, is defined in JIS X 4051, sec. 4.18.1.)

    Example of a table with inter-character spacing.
    Fig. 2.8: Example of a table with inter-character spacing.
  3. Tsumegumi (kerning / tracking): Text is set with negative inter-character space by arranging characters so that a portion of two character frames overlap each other. This is divided further into two types, depending on the methods used for inter-character space reduction. One method involves reducing by the same amount of inter-character space (even tsumegumi or tracking, see Fig. 2.9) and the other involves determining the amount of space to reduce based on the distance between the two letter faces of adjacent characters (face tsumegumi or letter face kerning, see Fig. 2.10).

    Example of even tsumegumi in horizontal writing mode. (The 1st line is the same text with solid setting, for comparison.)
    Fig. 2.9: Example of even tsumegumi in horizontal writing mode. (The 1st line is the same text with solid setting, for comparison.)
    Example of face tsumegumi in horizontal writing mode. (The 1st line is the same text with solid setting, for comparison.)
    Fig. 2.10: Example of face tsumegumi in horizontal writing mode. (The 1st line is the same text with solid setting, for comparison.)

    In the main text of books, the most reader-friendly approach is to use solid setting. However, if the character size is larger, the distance between characters may become unbalanced, and tsumegumi will be applied. For example, there are books where tsumegumi is used with headings set in large character sizes. These methods are rarely used in books, since ease of reading is very important, but in magazines or advertisements there are many more examples of tsumegumi. Magazines tend to use type to differentiate themselves from others, and so devices like this are sometimes used for that purpose.

2.2 Page Formats for Japanese Documents

2.2.1 Specification of Page Formats

The page format of a Japanese document is specified by:

  • Firstly, preparing a template of the page format, which determines the basic appearance of pages of the document;

  • Then, specifying the details of actual page elements based on the templates.

2.2.2 Basic Templates of Page Formats

Generally, books use only one template for page format, whereas magazines often use several templates.

Although in books, as will be mentioned in c of 2.2.5 Kihon-hanmen and Examples of Real Page Format, there tends to be one template for the page format, the basic pattern is typically adapted. For example, the table of contents may contain small modifications. Furthermore, there are many examples of indexes with a different page format than the basic page format, and vertically set books often have indexes in horizontal writing mode and sometimes multiple columns. This still holds true where the goal is to make the size of the hanmen for indexes close to the size of hanmen in the basic page format.

Magazines gather articles of different kinds. Often the page format will differ depending on the content of the article. For example, one part may have 9 point character size and 3 columns, and another part 8 point character size and 4 columns.

2.2.3 Elements of Page Formats

Example of a page format in vertical writing mode.
Fig. 2.11: Example of a page format in vertical writing mode.

The following are the basic elements of a page format. Fig. 2.11 illustrates an example of a page format in vertical writing mode).

  1. Trim size and binding side (vertically set Japanese documents are bound on the right-hand side, and horizontally set documents are bound on the left-hand side. See Fig. 2.12.)

  2. Principal text direction (vertical writing mode or horizontal writing mode).

  3. Appearance of the kihon-hanmen and its position relative to the trim size.

  4. Appearance of running heads and page numbers, and their positions relative to the trim size and kihon-hanmen.

Binding-side (bound on the right-hand side and bound on the left-hand side).
Fig. 2.12: Binding-side (bound on the right-hand side and bound on the left-hand side).

(note 1)

Establishing a kihon-hanmen may be seen as defining not only a rectangular area on a page, but also within that area an underlying, logical grid, to guide the placement of such things as characters, headings, and illustrations. However, once a kihon-hanmen is established, there is no absolute requirement to align characters with the grid, especially when setting characters inside a line. The only factors that influence the placement of characters are strong gravitational forces that (i) attract the first and last characters on a line to align with the border of the kihon-hanmen, and (ii) attract each line position to the line positions on which the kihon-hanmen is based.

It may help in understanding the basic concepts of Japanese layout and kihon-hanmen to think in terms of a slit-based model, rather than a grid-based model. Each slit is the full length of the lines on which the kihon-hanmen is based.

2.2.4 Elements of Kihon-hanmen

The kihon-hanmen is the hanmen style designed as the basis of a book. The following are the basic elements of the kihon-hanmen (see Fig. 2.13).

  1. Character size and typeface name

  2. Text direction (vertical writing mode or horizontal writing mode)

  3. Number of columns and column gap when using multi-column format

  4. Length of a line

  5. Number of lines per page (number of lines per column when using multi-column format)

  6. Line gap

Elements of kihon-hanmen. (Example in vertical writing mode.)
Fig. 2.13: Elements of kihon-hanmen. (Example in vertical writing mode.)

(note 1)

To understand the characteristics of Japanese composition, it is important to understand how the various elements of the kihon-hanmen are applied to a real page. The details will be explained in 2.5 Page wise Arrangement of Kihon-hanmen Elements.

(note 2)

The normative definition of kihon-hanmen is provided in JIS X 4051, sec. 7.5.

(note 3)

Format examples (including running heads and page numbers) and composition examples for kihon-hanmen in different trim sizes are available in JIS X 4051, annexes 3 and 4.

(note 4)

Depending on the application, character sizes can be specified in multiple ways. For books, character size is mainly specified using points or Q/q. Points are used for letterpress printing. In JIS Z 8305 (size units of printing type), one point is determined to be 0.3514mm. This is the size that is usually used. However, some commonly used applications adopt one point as 1/72 inch, ca. 0.3528mm. Q was used for photo typesetting. One Q is 0.25mm. It is very difficult to unify the unit sizes for character size specifications, because actual users prefer the unit to which they are accustomed. In some companies, multiple types of unit are used together.

2.2.5 Kihon-hanmen and Examples of Real Page Format

Below are several examples of how the basic page format is created, and how then various elements are placed on a real text page. (This and other aspects of how the various elements of the kihon-hanmen are arranged on each page are explained in 2.5 Page wise Arrangement of Kihon-hanmen Elements.)

  1. Realm and position of headings

    To set a heading, first establish a rectangular space based on a number of lines in the kihon-hanmen. For example, a '3 line space' means (3 * the size of the character frame used for the kihon-hanmen + 2 * the line gap in the kihon-hanmen). (Details of this processing are defined in JIS X 4051, sec. 8.3.3.d). The heading text is usually set in the centre of the rectangular space in the block direction, and indented from the line head. The size of the indent is usually specified as a number of characters in the kihon-hanmen. For example, a '4 character indent' means (4 * the size of the character frames used for establishing the kihon-hanmen). (See the example at Fig. 2.14.)

    Layout example of a heading based on the line positions established by the kihon-hanmen.
    Fig. 2.14: Layout example of a heading based on the line positions established by the kihon-hanmen.

    (note 1)

    Details of the different types of heading, creation of headings, methods for placing headings, etc. is explained in 4.1 Handling of Headings (including Page Breaks).

  2. Size of illustrations

    In horizontal writing mode with two columns, for example, the width of illustrations should, if at all possible, be either the width of one kihon-hanmen column or the width of the kihon-hanmen (see Fig. 2.15). The illustrations are usually set at the head or the foot of the page (see Fig. 2.15).

    Example of illustrations in two columns, horizontal writing mode.
    Fig. 2.15: Example of illustrations in two columns, horizontal writing mode.

    Also, in vertical writing mode, for example with three columns, the height of illustrations should, if at all possible, be either the height of one kihon-hanmen column or the height of the kihon-hanmen (see Fig. 2.16). The illustrations are usually set at the right side or left side of the kihon-hanmen (see Fig. 2.16).

    Example of illustrations in three columns, vertical writing mode.
    Fig. 2.16: Example of illustrations in three columns, vertical writing mode.

    (note 1)

    Details of illustration positioning is explained in 4.3 Positioning of Illustrations.

  3. Hanmen size for the table of contents

    The hanmen size for the table of contents of books is based on the size of the kihon-hanmen. There are many examples of tables of contents in vertical writing mode where the left-to-right size is identical to that of the kihon-hanmen, but the top-to-bottom size is a little bit smaller (see Fig. 2.17).

    Example of the design of the table of contents (TOC) in vertical writing mode.
    Fig. 2.17: Example of the design of the table of contents (TOC) in vertical writing mode.

    (note 1)

    There are cases when a different hanmen than the kihon-hanmen is used for positioning of running heads and page numbers. This will be discussed in 2.6.2 Principles of Arrangement of Running Heads and Page Numbers (see Fig. 2.51).

2.3 Vertical Writing Mode and Horizontal Writing Mode

2.3.1 Directional Factors in Japanese Composition

Japanese composition has two text directions. One is vertical direction (vertical writing mode), the other is horizontal direction (horizontal writing mode).

(note 1)

Ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters for Japanese composition have basically been designed to have a square character frame from the letterpress printing era on. Thus the same collection of printing types can be used in either vertical writing mode or horizontal writing mode, simply by changing the direction of text, (see Fig. 2.18). There were some attempts to develop printing types designed exclusively for horizontal writing mode, but they were not widely accepted.

Vertical writing mode and horizontal writing mode. (The arrows show the reading direction.)
Fig. 2.18: Vertical writing mode and horizontal writing mode. (The arrows show the reading direction.)

(note 2)

There is little market data comparing the number of pages with vertical writing mode and horizontal writing mode, but it is said that both are almost the same.

(note 3)

For official (e.g. governmental) documentation, horizontal writing mode is recommended. Educational material (with the exception of certain topics) is mostly in horizontal writing mode. Readers of "mobile novels" are increasing, and it is expected that in the future horizontal writing mode will increase in this area as well. However, most of the large newspapers are written completely in vertical writing mode, and most of the large journals for ordinary readers are almost completely set in vertical writing mode. In addition, novels, which are the most widely read kind of book publication, are almost completely in vertical writing mode (some readers say that they cannot read a novel if it is not in vertical writing mode). Hence it can be expected that the importance of vertical writing mode for Japanese will not change for the time being.

(note 4)

There is usually only one direction for all text throughout a book, but there are cases where horizontal writing mode is used in certain parts of vertically composed books (see Fig. 2.19). Tables, captions for illustrations, running heads, and page numbers are usually composed horizontally in a page with a vertical writing mode.

Example of horizontal writing mode in parts of vertically set books.
Fig. 2.19: Example of horizontal writing mode in parts of vertically set books.

2.3.2 Major Differences between Vertical Writing Mode and Horizontal Writing Mode

The following are major differences between vertical writing mode and horizontal writing mode.

  1. Arrangement of characters, lines, columns and pages; direction of page progression.

    (note 1)

    The positioning of characters, lines and paragraphs in vertical and horizontal writing mode is defined in JIS X 4051, sec. 7.4.4.

    1. Vertical writing mode. See Fig. 2.20 for an example of vertical writing mode with two columns per page.

      Direction of arrangement of characters in vertical writing mode.
      Fig. 2.20: Direction of arrangement of characters in vertical writing mode.
      1. Characters are arranged from top to bottom, lines are arranged from right to left.

      2. Columns are arranged from top to bottom. A book starts with the left (recto) side and progresses from right to left (see Fig. 2.21).

        Progression of pages for a vertically set books.
        Fig. 2.21: Progression of pages for a vertically set books.
    2. Horizontal composition. See Fig. 2.22 for an example of horizontal text layout with two-columns per page.

      Direction of arrangement of characters in horizontal writing mode.
      Fig. 2.22: Direction of arrangement of characters in horizontal writing mode.
      1. Characters are arranged from left to right, and lines are arranged from top to bottom.

      2. Columns are arranged from left to right. A book starts with the right (recto) side and progresses from left to right (see Fig. 2.23).

        Progression of pages for a horizontally set book.
        Fig. 2.23: Progression of pages for a horizontally set book.
  2. Orientation of Latin alphanumeric characters in a line.

    1. There are three ways to arrange Latin alphanumerics in vertical writing mode:

      1. One by one with the same normal orientation as that of Japanese characters. This is usually applied to one-letter alphanumerics or capitalized abbreviations (see Fig. 2.24).

        Arrangement of alphanumerics in vertical writing mode - normal orientation.
        Fig. 2.24: Arrangement of alphanumerics in vertical writing mode - normal orientation.

        (note 1)

        The alphanumeric characters used for this arrangement have different typographic features than those with proportional width used for Western text. They are of fixed-width and full-width design, and have been used this way since the letterpress printing era.

      2. Rotated 90 degrees clockwise. This is usually applied to English words or sentences (see Fig. 2.25).

        Arrangement of alphanumerics in vertical writing mode - rotated 90 degrees clockwise.
        Fig. 2.25: Arrangement of alphanumerics in vertical writing mode - rotated 90 degrees clockwise.

        (note 1)

        In Fig. 2.25, there are spaces before and after the character frame for the Western word "editor". These spaces are necessary for composition of mixed Japanese and Western text, and details will be provided in 3.2.6 Handling of Western Text in Japanese Text using Proportional Western Fonts.

      3. Set horizontally without changing orientation (called tate-chu-yoko, which means horizontal-in-vertical composition) (see Fig. 2.26). This is usually applied to two-digit numbers (see JIS X 4051, sec. 4.8 for the definition).

        Arrangement of alphanumerics in vertical writing mode - tate-chu-yoko.
        Fig. 2.26: Arrangement of alphanumerics in vertical writing mode - tate-chu-yoko.
    2. In horizontal writing mode there is only one way of arranging alphanumerics, i.e. normal orientation.

  3. Arrangement of tables and/or illustrations rotated 90 degrees clockwise or counter-clockwise for reasons of size. (This processing is defined in JIS X 4051, sec. 7.3.).

    1. In vertical writing mode, align the top of tables/illustrations to the right of the page (see Fig. 2.27).

      Example of arrangement of a table rotated 90 degrees clockwise in vertical writing mode.
      Fig. 2.27: Example of arrangement of a table rotated 90 degrees clockwise in vertical writing mode.
    2. In horizontal writing mode, align the top of tables/illustrations to the left of the page (see Fig. 2.28).

      Example of arrangement of a table rotated 90 degrees counterclockwise in horizontal writing mode.
      Fig. 2.28: Example of arrangement of a table rotated 90 degrees counterclockwise in horizontal writing mode.

      (note 1)

      The orientation is chosen to minimize interference with the overall reading flow of the book.

  4. Arrangement of an incomplete number of lines on a multi-column format page due to new recto, page break or other reasons. (The processing of new recto and page break is defined in JIS X 4051, sec. 8.1.1.).

    1. In vertical writing mode, just finish the line where it ends ("nariyuki"). The number of lines in each column is not uniform (see Fig. 2.29).

      How to process incomplete number of lines on a multi-column format page (vertically set book).
      Fig. 2.29: How to process incomplete number of lines on a multi-column format page (vertically set book).
    2. In horizontal writing mode, re-arrange columns so that each column has the same number of lines. In case the number of lines is not divisible by the number of columns, add the smallest number to make it divisible and re-arrange columns using the quotient as the number of lines so that only the last column shall have the incomplete number of lines (see Fig. 2.30).

      How to process incomplete number of lines on a multi-column format page (horizontally set book).
      Fig. 2.30: How to process incomplete number of lines on a multi-column format page (horizontally set book).

      (note 1)

      Neither horizontal nor vertical balance of column arrangement would break the stability of vertical page layout very much, while horizontal balance of column arrangement is determinant for horizontal page layout. In vertical text it doesn't matter too much whether columns are balanced or not. For horizontally set text it is best to balance columns wherever possible.

2.4 Specifying the Kihon-hanmen

2.4.1 Procedure for Defining the Kihon-hanmen

In Japanese composition, first the size of the kihon-hanmen is defined, using the square character frames of characters in solid setting. Taking this as a base, the position of the kihon-hanmen with regards to the trim size is then specified. The following are procedures for determining the size and position of the kihon-hanmen (see Fig. 2.31).

  1. Specifying the dimensions of the kihon-hanmen.

    1. For a document with a single column per page, specify the character size, the line length (the number of characters per line), the number of lines per page, and the line gap.

    2. For a document with multiple columns per page, specify the character size, the line length (the number of characters per line), the number of lines per column, the line-gap, and the number of columns and the column gap.

      Procedures to determine the size and position of the kihon-hanmen, step 1.
      Fig. 2.31: Procedures to determine the size and position of the kihon-hanmen, step 1.
  2. Determining the position of the kihon-hanmen relative to the trim size.

    There are various alternative methods for specifying the position of the kihon-hanmen relative to the trim size:

    1. Position vertically by centering the kihon-hanmen. Position horizontally by centering the kihon-hanmen.

    2. Position vertically by specifying the space size at the head (for horizontal writing mode) or the space at the foot (for vertical writing mode). Position horizontally by centering the kihon-hanmen.

    3. Position vertically by centering the kihon-hanmen. Position horizontally by specifying the space size of the gutter.

    4. Position vertically by specifying the space at the head (for horizontal writing mode) or the space at the foot (for vertical writing mode). Position horizontally by specifying the space size of the gutter.

    Procedures to determine the size and position of the kihon-hanmen, step 2.
    Fig. 2.32: Procedures to determine the size and position of the kihon-hanmen, step 2.

    (note 1)

    In most cases the kihon-hanmen is set at the horizontal and vertical center of the trim size, which should be the default positioning, but depending on the dimensions of the kihon-hanmen there may be cases where the default needs to be changed; for example, by moving the kihon-hanmen up, down, to the left or to the right of the default position.

    (note 2)

    It is technically possible to determine the dimensions of the kihon-hanmen by specifying the trim size and margins of all sides, but this method is not common in the tradition of Japanese composition. If this is the only way an implementation allows, the margins of each side need to be determined beforehand in relation to the dimensions of the kihon-hanmen and its position in the trim size.

2.4.2 Considerations in Designing the Kihon-hanmen

The following are considerations to take into account when designing the kihon-hanmen. (This topic is not about processing, but rather an explanation of design preferences. The definition of kihon-hanmen is given in JIS X 4051, sec. 7.4.1.)

  1. Trim size and margins. It would be best if the shape of the kihon-hanmen could be made similar to that of the trim size.

  2. Character size. Generally 9 point (about 3.2mm) type is common. Except for specialized publications such as dictionaries, the minimum size of type is 8 point (about 2.8mm).

    (note 1)

    In Western text layout, 10 point (about 3.5mm) or 12 point (about 4.2mm) type is common. This is mainly because of a difference in design principles between Japanese and Latin characters.

  3. Line length should be multiples of the character size (see Fig. 2.33).

    Line length should be multiples of the character size.
    Fig. 2.33: Line length should be multiples of the character size.

    (note 1)

    There are basically two reasons why line length should be multiples of the character size.

    1. For Japanese composition, all line lengths except that of the last line of the paragraph should, in principle, be the same.

    2. In principle, for printing, Japanese characters like ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters are uniformly designed in the same square character frame and they are set solid (no extra space between adjacent character frames).

    (note 2)

    The best line length (number of characters per line) is around 52 characters, maximum, in vertical writing mode, and 40 characters, maximum, in horizontal writing mode. If the trim size would take lines beyond the recommended length, consider using a multi-column format and making the line length shorter.

  4. Use the same amount of line gap throughout the book, except for special cases. The size of the kihon-hanmen in the block direction is specified using the number of lines and the size of the line-gap.

    (note 1)

    In Japanese composition, there are cases where ruby or emphasis (emphasis dots, bousen, underlines, etc.) are inserted between lines. In such cases the line gap is not changed but is kept constant (see Fig. 2.34). It is also possible to insert reference marks to notes between lines within the main text. This case is handled in the same manner. If these elements are likely to occur in text, the line gap established during the kihon-hanmen design needs to be of an adequate size to accommodate them. Further explanations about the placement of ruby will be given in 3 Line Composition.

    Inserting ruby or other items between lines.
    Fig. 2.34: Inserting ruby or other items between lines.

    (note 2)

    Warichu (inline cutting note) juts into the line gap on either side of a line. The basic line gap isn't changed where warichu occurs (the line gap between warichu itself and the adjacent lines looks narrower than for the rest of the line), so when warichu is likely to occur in text, the line gap for the kihon-hanmen may be set slightly larger than normal to accommodate it. The same is true for tate-chu-yoko or subscript and superscript (ornament characters). Further explanation of the placement of warichu and other items is provided in 3 Line Composition.

    Example of inter-line processing with warichu between lines.
    Fig. 2.35: Example of inter-line processing with warichu between lines.

    (note 3)

    It is common that the line gap for the kihon-hanmen is set to a value between a half em space and the one em space of the character frame used for the kihon-hanmen. A half em space can be chosen in cases where the line length is short, but a one em space or close to it is more appropriate when the line length is longer than 35 characters.

    (note 4)

    Unless ruby or other design elements are placed in the space between lines (e.g. for books such as classics, with many annotations), there is no need to make the line-gap larger than full-width, since this would decrease legibility.

    (note 5)

    It is said that the standard line-gap in Western text layout is a one third em space, which is smaller than that in Japanese composition. This difference again comes from the different approach to the design of Latin and Japanese characters.

    (note 6)

    There is another method of specifying the kihon-hanmen that uses line feeds rather than line gaps. Line feed is the distance between two adjacent lines measured from their reference points (see Fig. 2.36). The reference point differs from implementation to implementation, however, in vertical writing mode the horizontal center of the character frame is usually used, and with horizontal writing mode, the vertical center of the character frame is used. When the character size is the same for every character, the following calculation is used:

    • line feed = character size / 2 + line gap + character size / 2 = character size + line gap

    • line gap = line feed - character size

    Specifying kihon-hanmen with line feed.
    Fig. 2.36: Specifying kihon-hanmen with line feed.

The size of the kihon-hanmen in this case can be calculated by following method:

  • Vertical writing mode with one column

    Width of kihon-hanmen = character size × number of lines per page + line gap × (number of lines per page − 1)

    e.g.

    298 point = 9 point × 18 lines + 8 point × (18 lines − 1)

    Height of kihon-hanmen = character size × number of characters per line

    e.g.

    468 point = 9 point × 52 characters

  • Vertical writing mode with multi columns

    Width of kihon-hanmen = character size × number of lines per column + line gap × (number of lines per column − 1)

    e.g.

    309 point = 9 point × 21 lines + 6 point × (21 lines − 1)

    Height of kihon-hanmen = character size × number of characters per line × number of columns + column gap × (number of columns − 1)

    e.g.

    468 point = 9 point × 25 characters × 2 columns + 18 point × (2 columns − 1)

  • Horizontal writing mode with one column

    Width of kihon-hanmen = character size × number of characters per line

    e.g.

    315 point = 9 point × 35 characters

    Height of kihon-hanmen = character size × number of lines per page + line gap × (number of lines per page − 1)

    e.g.

    468 point = 9 point × 28 lines + 8 point × (28 lines − 1)

  • Horizontal writing mode with multi columns

    Width of kihon-hanmen = character size × number of characters per line × number of columns + column gap × (number of columns − 1)

    e.g.

    320 point = 8 point × 19 characters × 2 columns + 16 point × (2 columns − 1)

    Height of kihon-hanmen = character size × number of lines per column + line gap × (number of lines per column − 1)

    e.g.

    476 point = 8 point × 40 lines + 4 point × (40 lines − 1)

2.5 Page wise Arrangement of Kihon-hanmen Elements

2.5.1 Examples of Items Jutting Out of the Kihon-hanmen

The various elements of a page should remain inside the boundaries of the kihon-hanmen. However, there are exceptions such as the following:

  1. Ruby or emphasis marks (bousen, emphasis dots, etc.) at the before edge of the hanmen, are placed outside the hanmen (see Fig. 2.37). The same applies in cases where ruby, underline, etc. appear beyond the after edge of the hanmen. Like the handling of exceptions mentioned below, the purpose here is to preserve the line positions established for the kihon-hanmen. This technique can also be used for reference marks associated with lines of text.

    Example of ruby annotation placed outside of the kihon-hanmen.
    Fig. 2.37: Example of ruby annotation placed outside of the kihon-hanmen.
  2. When there are inline elements whose dimensions extend beyond the before edge and the after edge of a line of characters as determined by the kihon-hanmen, and when those elements appear in the first or last line of the hanmen, the parts that jut out beyond the regular line of characters also jut out of the hanmen area. For example, this is the case when the width of a sequence of characters which are set to tate-chu-yoko is wider than the characters set for the kihon-hanmen. In addition, warichu (inline cutting note) or subscript and superscript (ornament characters) are handled in the same way. (The processing rules for this item and the previous item are defined in JIS X 4051, sec. 12.1.1.)

  3. Line adjustment by hanging punctuation is only necessary for full stops (cl-06) and commas (cl-07) when they would otherwise need to be wrapped to the line head. The character is placed so that it touches the hanmen at the line end (see Fig. 2.38). (Hanging punctuation is not defined in JIS X 4051, but there is an explanation in sec. 8.1, c.)

    Example of IDEOGRAPHIC COMMA and IDEOGRAPHIC FULL STOP placed below the kihon-hanmen.
    Fig. 2.38: Example of IDEOGRAPHIC COMMA and IDEOGRAPHIC FULL STOP placed below the kihon-hanmen.

    (note 1)

    Line adjustment by hanging punctuation is a way of reducing the processing cost of line adjustment by reducing the need to change inter-character space.

    (note 2)

    A lot of books apply hanging punctuation.

  4. Illustrations and tables are normally placed inside the area defined by the kihon-hanmen. However, there may also be cases in which a particular illustration or table juts outside the kihon-hanmen.

    1. Cases in which it is necessary to make the illustration or table larger than the kihon-hanmen, because reducing its size would make it unreadable.

    2. For the sake of visual effect, the illustration may bleed into the complete paper area. This is not often used in books, but is often used in magazines (see Fig. 2.39).

      Example of bleeds.
      Fig. 2.39: Example of bleeds.
  5. Magazines may place the captions of illustrations outside the column area or in the column gap. (Some people regard this as bad style.)

2.5.2 Line Positioning based on the Kihon-hanmen Design

In principle, pagewise positioning of lines relies on the line positions established for the kihon-hanmen. This holds for lines with ruby or emphasis dots as shown in Fig. 2.34. Even when lines contain characters that are smaller than the character size used for the kihon-hanmen (as shown in Fig. 2.40), the line positions used for the kihon-hanmen continue to be used as the basic guide lines. This is so that following lines with normal-sized characters still naturally fall into the line positions established for the kihon-hanmen.

Positioning of lines with a smaller size of text.
Fig. 2.40: Positioning of lines with a smaller size of text.

(note 1)

Characters within brackets are made smaller, since the text is an additional explanation. Such cases are handled in the following three ways. The first method, making only characters in restricted places smaller, is the most commonly used.

  1. Make the characters smaller only in restricted places, for example for references.

  2. Make all characters within brackets smaller (as shown in Fig. 2.40).

  3. Make all characters within brackets the same size as the character size established for the kihon-hanmen.

The following are exceptions when handling line position:

  1. When inserting more than one illustration or table item in horizontal writing mode, assuming that there is no text to the left or right of the items, the items may either slip off the lines established for the kihon-hanmen (see Fig. 2.41), or stick to the lines (see Fig. 2.42). The former approach is used, whenever possible, to achieve inter-character spacing before and after illustrations or tables constant. (This method is often used in books.) (This processing method is defined in JIS X 4051, sec. 10.3.2., d.)

    Positioning of lines with multiple illustrations - 1.
    Fig. 2.41: Positioning of lines with multiple illustrations - 1.
    Positioning of lines with multiple illustrations - 2.
    Fig. 2.42: Positioning of lines with multiple illustrations - 2.
  2. The size of characters in endnotes inserted between paragraphs or those in footnotes at the bottom of the page (in horizontal writing mode) is smaller than the character size established for the kihon-hanmen. As a result, the character size and line gap are also smaller, and so the line positions are no longer identical to those established for the kihon-hanmen. As an example, Fig. 2.43 shows the position of an endnote between paragraphs in vertical writing mode. (The processing of endnotes is defined in JIS X 4051, sec. 9.3, and the processing of footnotes in sec. 9.4.)

    Positioning of an endnote in vertical writing mode.
    Fig. 2.43: Positioning of an endnote in vertical writing mode.
  3. As mentioned above, the position of a heading may not be identical to the lines established for the kihon-hanmen. Nevertheless, in the block direction, headings base their alignment on the line positions established for the kihon-hanmen (see Fig. 2.14).

2.5.3 Character Positioning based on Kihon-hanmen Design

In principle, the characters in each line follow the solid setting positions of characters established for the kihon-hanmen. However, as already shown in some of the previous figures, there are examples where this is not the case. Such cases are rather common, and here we will show some prototypical examples (details will be given in 3 Line Composition).

(note 1)

Where character sizes differ from the solid set sizes established for the kihon-hanmen, line lengths may not be identical with the line length of the kihon-hanmen; it is necessary to align the ends of the lines, with the exception of the last line in a paragraph. The processing method for this is explained in 3.8 Line Adjustment.

  1. When 9pt is the character size used to establish the kihon-hanmen, characters smaller than 9pt may be inserted in part of a line (see Fig. 2.40). In such cases, the parts set at 9pt and any parts set at a smaller, say, 8pt size both use solid setting, with character frames at the respective sizes for each part.

  2. In cases where proportional Latin letters are rotated 90 degrees clockwise (see Fig. 2.25), the proportional letters are placed according to their proportional widths. Hence, they do not fit to the character positions established for the kihon-hanmen (see Fig. 2.44). Japanese letters following the Latin letters consequently slip away from the default positions as well.

    Positioning of a mixture of Western and Japanese letters in a line.
    Fig. 2.44: Positioning of a mixture of Western and Japanese letters in a line.
  3. There are several methods for positioning opening brackets (cl-01) at the beginning of a line (details are explained in 3.1.5 Positioning of Opening Brackets at Line Head). Because an opening bracket is not a full-width character, in cases where the indentation of the first line of a paragraph is a one em space, or if the tentsuki position is used for the bracket (that is, there is no space at the line head), the character following the bracket will be in a position which does not fit to the character positions established for the kihon-hanmen (see Fig. 2.45). However, the adaptations made during the alignment of line ends will ensure that the character at the end of a line is at a position that fits with the kihon-hanmen.

    Example of positioning of characters off the kihon-hanmen position due to opening brackets at the line head.
    Fig. 2.45: Example of positioning of characters off the kihon-hanmen position due to opening brackets at the line head.
  4. 3 Line Composition explains that full stops (cl-06), commas (cl-07), opening brackets (cl-01) and closing brackets (cl-02) are half-width. If these punctuation marks and brackets are adjacent to ideographic (cl-19), katakana (cl-16) or hiragana (cl-15) characters, in principle there should be a half em space before or after the punctuation mark or brackets, so that these occupy in effect a full-width size. However, if they are adjacent to other punctuation marks or brackets, the half em space is not used. This is done to improve the visual appearance. In such cases, the character positions are different than the positions established when defining the kihon-hanmen (see Fig. 2.46).

    Example of lines with consecutive punctuation marks.
    Fig. 2.46: Example of lines with consecutive punctuation marks.
  5. 3 Line Composition explains the principle that closing brackets (cl-02), full stops (cl-06) and commas (cl-07) should not be placed at the line head. If by simple sequential placement these characters would appear at the line head or at the line end, some kind of adjustment becomes necessary. A similar adjustment is required for characters that should not be placed at the end of a line, such as opening brackets (cl-01). As a result of such adjustment, it may happen that other characters are placed at positions which are different from those established for the kihon-hanmen.

    Example of line adjustment to avoid those characters which shall not start and end a line.
    Fig. 2.47: Example of line adjustment to avoid those characters which shall not start and end a line.

2.6 Running Heads and Page Numbers

2.6.1 Positioning of Running Heads and Page Numbers

Typical positions of running heads and page numbers for vertically set books with double running heads (see 2.6.3 Ways of Arranging Running Heads and Page Numbers) are as shown in Fig. 2.48.

Typical positioning of running heads and page numbers for vertically set books with double running heads.
Fig. 2.48: Typical positioning of running heads and page numbers for vertically set books with double running heads.

Typical positions of running heads and page numbers for horizontally set books with double running heads (see 2.6.3 Ways of Arranging Running Heads and Page Numbers) are as shown in Fig. 2.49.

Typical positioning of running heads and page numbers for horizontally set books with double running heads.
Fig. 2.49: Typical positioning of running heads and page numbers for horizontally set books with double running heads.

In principle, positions of running heads and page numbers should be specified relative to the kihon-hanmen, not with absolute coordinates in the trim size. (Positioning of running heads is defined in JIS X 4051, sec. 7.6.4. Positioning of page numbers is defined in JIS X 4051, sec. 7.5.4.)

Example:

Positioning a horizontal running head above the top left corner (to head and fore-edge) of the kihon-hanmen in a typical vertically set book (see Fig. 2.50).

9 points above the kihon-hanmen (vertical space)

9 points from the left edge of the kihon-hanmen (horizontal space)

Positioning of a running head (vertical writing mode).
Fig. 2.50: Positioning of a running head (vertical writing mode).

The following recommendations should be taken into account when positioning running heads and page numbers with reference to the kihon-hanmen.

  1. When positioning horizontal running heads and page numbers with reference to the kihon-hanmen in vertically set books, the amount of vertical space between the edge of the kihon-hanmen and the running head is a one em space as established for the kihon-hanmen. If the kihon-hanmen of the book is horizontally set, take more vertical space than the character size in the kihon-hanmen.

  2. Regardless of the direction of text in the kihon-hanmen of a book, horizontal running heads and page numbers on the left page should be aligned either at the left edge of the kihon-hanmen or one em space to the right of the left edge. On the right page, the tail of the running heads or page numbers should be aligned either at the right edge of the kihon-hanmen or one full-width space to left of the right edge.

  3. Regardless of the direction of text in a book, when arranging running heads and page numbers together on the same horizontal line, the space between the running head and the page number should be double or one and a half times the character size of the running head. On the left page, the page number should be set at the left side and the running head should be set at the right side. On right-hand pages, the page number should be set at the right side and the running head should be set at the left side. The exact positions of the page numbers are given by the instructions above (see b).

  4. When positioning running heads and page numbers vertically to the fore-edge of the kihon-hanmen in a vertically set book (see spread (e) in Fig. 2.48, for example), the minimum horizontal distance from the kihon-hanmen should be the same as that of the line gap of the kihon-hanmen. The top of the running head should be positioned approximately four kihon-hanmen characters below the head, and the bottom of the page numbers should be positioned approximately five kihon-hanmen characters above the foot.

    (note 1)

    In general, ideographic numerals (一二三四五六七八九〇) are used for vertically set page numbers, and European numerals for horizontal pagination. When using independent pagination for the front matter, small Roman numerals are used for horizontal pagination.

2.6.2 Principles of Arrangement of Running Heads and Page Numbers

Positioning of all running heads and page numbers in the same book should be consistent.

(note 1)

Even on a page with a text area smaller in size than that of the kihon-hanmen, such as for a table of contents or index, positioning of the running head and page number relative to the trim size will remain the same. Therefore, the positioning of running heads and page numbers relative to those areas smaller than the kihon-hanmen is different. Fig. 2.51 below demonstrates the respective positions of the hanmen for a table of contents and running heads or page numbers. As shown in Fig. 2.17, this hanmen is smaller than the kihon-hanmen. Fig. 2.52 demonstrates the related positions of running heads and page numbers and the hanmen of indexes. These hanmen are not only 4 points smaller at the left and right, but also 5 points smaller at the top and bottom.

Positioning of running heads and page numbers on TOC pages for which the hanmen is smaller in size than the kihon-hanmen.
Fig. 2.51: Positioning of running heads and page numbers on TOC pages for which the hanmen is smaller in size than the kihon-hanmen.
Positioning of running heads and page numbers on index pages for which hanmen is smaller in size than the kihon-hanmen.
Fig. 2.52: Positioning of running heads and page numbers on index pages for which hanmen is smaller in size than the kihon-hanmen.

Because the start of a page will be on the recto side, the right-hand page of a spread in a vertically set book is always an even page and the left-hand page is always an odd page (see Fig. 2.53). Likewise, the left-hand page of a spread in a horizontally set book is always an even page and the right-hand page is always an odd page (see Fig. 2.54).

Page numbers on a spread in a vertically set book.
Fig. 2.53: Page numbers on a spread in a vertically set book.
Page numbers on a spread in a horizontally set book.
Fig. 2.54: Page numbers on a spread in a horizontally set book.

2.6.3 Ways of Arranging Running Heads and Page Numbers

There are two ways to arrange running heads. One is the single running head method and the other is the double running head method. (Arrangement of running heads is defined in JIS X 4051, sec. 7.6.2. Page Numbers are defined in sec. 7.5.2.).

Double running head method.
Fig. 2.55: Double running head method.
Single running head method.
Fig. 2.56: Single running head method.

(note 1)

In general, there will be only one running head per page. However, in some cases, such as in dictionaries, multiple running heads are printed on each page to indicate contents.

(note 2)

In general, there will be only one page number per page. However in some cases multiple page numbers are printed on each page as in the following examples:

  1. When a horizontally set index and/or bibliography appears at the end of a volume in a vertically set book, both reverse pagination and continuous pagination are printed.

  2. For multivolume works, both serial page numbers throughout the work and page numbers per volume are printed.

  1. In the double running head method, a higher-level title, such as that of the chapter or book, is used for the running heads on the even pages, and a lower-level title, such as that for a section, on the odd pages. Where there are no differing levels of titles, such as on the page containing the table of contents, the same running head is used on both even and odd pages.

    (note 1)

    Which information is used for the running heads depends on the content of the book. Given that the main purpose of running heads is to signpost to readers what is written on each page, or the content of the current page, it does not make much sense to use the book title for the running head. The most common approach for a book with three levels of headings, such as chapter, section and subsection, is to use the highest level heading (i.e. chapter) and the second level heading (i.e. section).

  2. In the single running head method, one of the headings between the top and third levels is used.

  3. In principle, the contents of running heads will be the same as those of headings with the following differences:

    1. Numbers and words in Latin alphanumeric characters in vertically set headings in vertically set books should be changed to horizontal notation for horizontally set running heads (see 2.3.2 Major Differences between Vertical Writing Mode and Horizontal Writing Mode).

    2. If headings are too long, they should be made shorter by paraphrasing them in fewer characters. Running heads with too many characters will not look good.

    3. For certain publications, such as a collection of monographs, the names of authors may be added in parentheses at the end of the running head.

  4. In principle, the text direction of running heads and page numbers should be the same as that of the kihon-hanmen. For vertically set books, however, it is more common to set running heads and page numbers horizontally.

  5. In principle, for the single running head method running heads are printed on all odd pages, and for the double running head method on all even and odd pages. However, for the sake of appearance, running heads may be omitted as follows:

    1. Pages on which running heads should be hidden:

      1. Naka-tobira and han-tobira.

      2. Pages where a running head overlaps with other elements such as illustrations.

      3. Blank pages.

    2. Pages on which running heads may be hidden:

      1. Pages where a figure or a table is positioned adjacent to the running head.

      2. Pages with a heading right after a new recto or new page.

  6. In principle, page numbers are printed on all pages. However, for the sake of appearance, they may be omitted as follows:

    1. Pages on which page numbers should be hidden:

      1. Pages on which a illustration or a table is positioned adjacent to the page number.

      2. Blank pages.

    2. Pages on which page numbers may be hidden:

      1. Divisional title and simplified divisional title pages.

      2. Pages in horizontally set books with a page number placed in the margin at the top of the page, and with a heading at the beginning of a new recto or new page. (In this case, it is also possible to move the page numbers to the center of the margin at the foot of the page.)

    (note 1)

    Pages are not counted in cases such as the following:

    • If a different type or color of paper is used for the main title page,

    • if a frontispiece is inserted in the opening page of a book; or

    • if an illustration of the enclosure or a divisional title is present in the main text.

  7. There are two types of page numbering. "Continuous pagination" means that page numbers continue throughout the whole book. "Independent pagination" means that page numbers start from "1" separately at beginning of the front matter and back matter. There is also, for example in manuals, the method of starting each chapter from page number "1". (In such cases, it is common that the name of the chapter is added as a prefix before the page number.)

    (note 1)

    If the front matter and the main text have different page numbers, each starts with page number "1". In this case, it is common to use Roman numerals for the pages of the front matter, in order to distinguish them from the main text.

    (note 2)

    For vertically set books with indexes in horizontal writing mode, the following methods are available.

    1. Reverse pagination. The index reads from the end of the book, and page numbers are added starting with "1" from the end of the book and flow in the same order as the index.

    2. Continuous pagination. The index reads from the end of the book, but page numbers start with "1" and flow in the same order as the book. (The index pages flow in the reverse order to the page numbers.)

    3. Both reverse pagination and continuous pagination. In this case, the page numbers for continuous pagination are in the same position as the page numbers of the main text, and page numbers in reverse pagination are in a different position (for example, if serial pagination is in the foot of the page, reverse pagination is in the head). Often other methods are applied to distinguish the different paginations. For example, Arabic numbers are used for both continuous pagination and reverse pagination, but for reverse pagination, brackets are added around the numbers.

3 Line Composition


3.1 Line Composition Rules for Punctuation Marks

3.1.1 Differences in Vertical and Horizontal Composition in Use of Punctuation Marks

There are some punctuation marks that are used uniquely in either vertical writing mode or horizontal writing mode. In this document, characters and symbols are treated as members of a character class, classified by their behavior for composition. Each class name is followed by class id, such as opening brackets (cl-01). Details are explained in 3.9 About Character Classes. The following are some typical examples:

  1. Full stops (cl-06) and commas (cl-07)

    1. In vertical writing mode, IDEOGRAPHIC FULL STOP "。" and IDEOGRAPHIC COMMA "、" are used for full stops (cl-06) and commas (cl-07).

    2. In horizontal writing mode, there are three conventions in choice of symbols for full stops (cl-06) and commas (cl-07):

      1. Using COMMA "," and FULL STOP "." (see Fig. 3.1).

        Example text using COMMA and FULL STOP.
        Fig. 3.1: Example text using COMMA and FULL STOP.
      2. Using COMMA "," and IDEOGRAPHIC FULL STOP "。" (see Fig. 3.2).

        Example text using COMMA and IDEOGRAPHIC FULL STOP.
        Fig. 3.2: Example text using COMMA and IDEOGRAPHIC FULL STOP.
      3. Using IDEOGRAPHIC COMMA "、" and IDEOGRAPHIC FULL STOP "。" (see Fig. 3.3).

        Example text using IDEOGRAPHIC COMMA and IDEOGRAPHIC FULL STOP.
        Fig. 3.3: Example text using IDEOGRAPHIC COMMA and IDEOGRAPHIC FULL STOP.

      (note 1)

      In horizontal writing mode, there are many cases of composition that mixes Japanese and Western text. The convention shown in (i) is a way to apply the same comma and full stop to both Western and Japanese texts for consistency, and is common in books on science and technology. The convention shown in (ii) was invented because in (i) FULL STOP "." appears too small for Japanese texts and using IDEOGRAPHIC FULL STOP "。" for period looks better. This convention has been adopted for Japanese official publications. (In the past, COMMA "," and FULL STOP "." were used for some official publications.)

  2. LEFT CORNER BRACKET "「", RIGHT CORNER BRACKET "」", LEFT DOUBLE QUOTATION MARK "“" and RIGHT DOUBLE QUOTATION MARK "”"

    1. In vertical writing mode, LEFT CORNER BRACKET "「" and RIGHT CORNER BRACKET "」" are used for quotations (see Fig. 3.4).

      Examples of quoted text using LEFT CORNER BRACKET and RIGHT CORNER BRACKET.
      Fig. 3.4: Examples of quoted text using LEFT CORNER BRACKET and RIGHT CORNER BRACKET.
    2. In horizontal writing mode, pairs of LEFT DOUBLE QUOTATION MARK "“" and RIGHT DOUBLE QUOTATION MARK "”" or pairs of LEFT SINGLE QUOTATION MARK "‘" and RIGHT SINGLE QUOTATION MARK "’" may be used in place of LEFT CORNER BRACKET "「" and RIGHT CORNER BRACKET "」" (see Fig. 3.5).

      Examples of quoted text using LEFT DOUBLE QUOTATION MARK and RIGHT DOUBLE QUOTATION MARK.
      Fig. 3.5: Examples of quoted text using LEFT DOUBLE QUOTATION MARK and RIGHT DOUBLE QUOTATION MARK.

      (note 1)

      This is because LEFT CORNER BRACKET "「" and (especially) RIGHT CORNER BRACKET "」" may not look good in horizontal writing mode, but adoption of corner brackets for horizontal writing mode seems to be increasing.

      (note 2)

      Though REVERSED DOUBLE PRIME QUOTATION MARK "〝" and LOW DOUBLE PRIME QUOTATION MARK "〟" are similar to double quotation marks in appearance (see Fig. 3.6) they are exclusively used for vertical writing mode and are not to be used in horizontal writing mode.

      Examples of quoted text using REVERSED DOUBLE PRIME QUOTATION MARK and LOW DOUBLE PRIME QUOTATION MARK.
      Fig. 3.6: Examples of quoted text using REVERSED DOUBLE PRIME QUOTATION MARK and LOW DOUBLE PRIME QUOTATION MARK.

      (note 3)

      LEFT DOUBLE QUOTATION MARK "“" and RIGHT DOUBLE QUOTATION MARK "”" are exclusively for horizontal writing mode and not to be used in vertical writing mode. Also, LEFT SINGLE QUOTATION MARK "‘" and RIGHT SINGLE QUOTATION MARK "’" are exclusively for horizontal writing mode and not to be used in vertical writing mode. However, in vertical writing mode, when Western characters (cl-27) are composed rotated 90 degrees clockwise, these quotation marks are sometimes used.

  3. LEFT SQUARE BRACKET "[", RIGHT SQUARE BRACKET "]", LEFT TORTOISE SHELL BRACKET "〔" and RIGHT TORTOISE SHELL BRACKET "〕"

    LEFT TORTOISE SHELL BRACKET "〔" and RIGHT TORTOISE SHELL BRACKET "〕" are vertical variants of LEFT SQUARE BRACKET "[" and RIGHT SQUARE BRACKET "]", which are used in horizontal writing mode. Square brackets should be used in horizontal writing mode except for special cases.

(note 1)

The position of the letter face of commas (cl-07) and full stops (cl-06) within the character frame differs in vertical and horizontal writing modes. The same letter face can be used for opening brackets (cl-01), closing brackets (cl-02) and hyphens (cl-03) in both vertical and horizontal writing mode by rotating clockwise 90 degrees to the inline direction. The position of the letter face of small kana (cl-11) symbols within the character frame is different in vertical and horizontal writing modes. For KATAKANA-HIRAGANA PROLONGED SOUND MARK "ー", the difference between vertical and horizontal writing modes is not only in the orientation of the letter form to the inline direction, but also the shape of the symbol (see Fig. 3.7).

KATAKANA-HIRAGANA PROLONGED SOUND MARK for vertical and horizontal writing modes.
Fig. 3.7: KATAKANA-HIRAGANA PROLONGED SOUND MARK for vertical and horizontal writing modes.

3.1.2 Positioning of Punctuation Marks (Commas, Periods and Brackets)

The positioning of punctuation marks (commas, periods and brackets) in a line proceeds as follows.

(note 1)

Basic processing of characters and symbols, including punctuation marks, which are subject to considerations of line head wrapping, line end wrapping and inter-character space adjustment, will be described in detail in 3.9 About Character Classes. All combinations of character class are provided as a complete table in Appendix B Spacing between Characters.

The character advance of commas (cl-07), full stops (cl-06), opening brackets (cl-01), closing brackets (cl-02) and middle dots (cl-05) is half-width (half em). But when those punctuation marks are placed side-by-side with ideographic (cl-19), hiragana (cl-15), or katakana (cl-16) characters, in principle, a given amount of space will be inserted before or after the symbols, which makes them appear as if they were intrinsically full-width (one em) (see Fig. 3.8). Space is inserted before and after middle dots (cl-05). This principle makes the symbols consistent with ideographic (cl-19), hiragana (cl-15) and katakana (cl-16) characters in character width, and at the same time the space for punctuation helps to make the organization of text clearer. The space size added before or after punctuation marks is subject, in principle, to line adjustment and may eventually be removed, except for that added after full stops (cl-06). (Details of line adjustment are discussed in 3.8 Line Adjustment).

Character widths of commas, periods, and the space size appended before and/or after the symbols.
Character widths of commas, periods, and the space size appended before and/or after the symbols.
Fig. 3.8: Character widths of commas, periods, and the space size appended before and/or after the symbols.
  1. After commas (cl-07), a half em space is added, in principle.

  2. After full stops (cl-06), in the middle of a line, a half em space is added. At the end of a line, a half em space is added, in principle.

  3. Before opening brackets (cl-01), a half em space is added, in principle.

  4. After closing brackets (cl-02), a half em space is added, in principle.

  5. Before and after middle dots (cl-05), a quarter em space is added, in principle.

(note 1)

In font implementations, punctuation marks can be given a different character width, but it is expected that the font is capable of following the line composition rules explained here to produce the final result. For example, when opening brackets (cl-01) and closing brackets (cl-02) are implemented with full-width size, it is possible that a minus half em space is inserted between adjacent closing brackets (cl-02) and opening brackets (cl-01) (Some implementations prepare minus half em spaces and quarter em spaces). In letterpress printing, it was also common practice to combine punctuation marks with a half-width body and half em spaces in order to make it easier to remove the space later for adjustment. Because of that, the types were picked up except for the punctuation marks at the type-picking phase, following the manuscript, and the punctuation marks were picked only when they were necessary in composing a page. Later, with the increasing adoption of Monotype machines, punctuation marks with a full-width body became popular and both full-width and half-width punctuation marks have been used, mixed together, since then.

Positioning of parentheses and brackets. (The left-hand side shows an example of setting them solid.)
Fig. 3.9: Positioning of parentheses and brackets. (The left-hand side shows an example of setting them solid.)

(note 2)

Among opening brackets (cl-01) and closing brackets (cl-02), LEFT PARENTHESIS "(", RIGHT PARENTHESIS ")", LEFT ANGLE BRACKET "〈" and RIGHT ANGLE BRACKET "〉" are used to indicate supplementary explanations, and in that case their usage differs slightly from other opening brackets (cl-01) and closing brackets (cl-02). To reflect the difference, there is an alternative convention to not append a half em space before or after the parentheses and angle brackets, and instead just set them solid (see Fig. 3.9).

3.1.3 Exceptional Positioning of Ideographic Comma and Katakana Middle Dot

The space usually added after IDEOGRAPHIC COMMA "、" and the space before and after KATAKANA MIDDLE DOT "・" are omitted, in principle, for cosmetic reasons in the following cases.

  1. In vertical writing mode, ideographic numerals and IDEOGRAPHIC COMMA "、" used as a decimal separator are set solid (as in the right line in Fig. 3.10).

    Example of  exceptional positioning of the IDEOGRAPHIC COMMA.
    Fig. 3.10: Example of exceptional positioning of the IDEOGRAPHIC COMMA.

    (note 1)

    In vertical writing mode, ideographic digits used with IDEOGRAPHIC COMMA "、" to represent an approximate number are expected to be set solid too (as in the right line in Fig. 3.11).

    Example of the positioning of IDEOGRAPHIC COMMA with ideographic digits to represent an approximate number.
    Fig. 3.11: Example of the positioning of IDEOGRAPHIC COMMA with ideographic digits to represent an approximate number.
  2. In vertical writing mode, ideographic digits and KATAKANA MIDDLE DOT "・" representing a decimal point are set solid (as in the right line in Fig. 3.12).

    Example of the exceptional positioning of KATAKANA MIDDLE DOT.
    Fig. 3.12: Example of the exceptional positioning of KATAKANA MIDDLE DOT.

    (note 1)

    In vertical writing mode, when KATAKANA MIDDLE DOT "・" is used as a member of unit symbols (cl-25) in unit symbols, grouped numerals (cl-24), and Western characters (cl-27) in mathematical and chemical formulae, before and after KATAKANA MIDDLE DOT "・" is set solid.

3.1.4 Positioning of Consecutive Opening Brackets, Closing Brackets, Commas, Full Stops and Middle Dots

In cases where multiple punctuation marks, such as opening brackets (cl-01), closing brackets (cl-02), commas (cl-07), full stops (cl-06) and middle dots (cl-05), come one after the other, the following space adjustments are made for aesthetic reasons (see Fig. 3.13). Note also that the half em and quarter em spaces added before or after punctuation marks, including the half em space after full stops (cl-06) appearing in the middle of a line, are subject, in principle, to line adjustment and may eventually be removed, except for those added after full stops (cl-06). (See 3.8 Line Adjustment for more about line adjustment.) For more information about the positioning of closing brackets (cl-02), full stops (cl-06), commas (cl-07) and middle dots (cl-05) at line end, see 3.1.9 Positioning of Closing Brackets, Full Stops, Commas and Middle Dots at Line End.

  1. When closing brackets (cl-02) come immediately after commas (cl-07) or full stops (cl-06), remove the default half em space between them and, in principle, add a half em space after the closing brackets (see Fig. 3.13 ①).

  2. When commas (cl-07) come immediately after closing brackets (cl-02), remove the default half em space between them and, in principle, add a half em space after the comma. When full stops (cl-06) come immediately after closing brackets (cl-02), remove the default half em space between them and, in middle of a line, add a half em space after the full stop; at the end of a line, in principle, add a half em space after the full stop (see Fig. 3.13 ②).

  3. When opening brackets (cl-01) come immediately after commas (cl-07), in principle, add a half em space between them (see Fig. 3.13 ③). When opening brackets (cl-01) come immediately after full stops (cl-06) in the middle of a line, add a half em space between them. Note that when full stops (cl-06) come in the bottom of lines, in principle, insert a half space after full stops (cl-06).

  4. When opening brackets (cl-01) come immediately after closing brackets (cl-02), in principle, add a half em space between them (see Fig. 3.13 ④).

  5. When opening brackets (cl-01) come immediately after other opening brackets (cl-01), set them solid and, in principle, add a half em space before the first one (see Fig. 3.13 ⑤).

  6. When closing brackets (cl-02) come immediately after other closing brackets (cl-02), set them solid and, in principle, add a half em space after the last closing bracket (see Fig. 3.13 ⑥).

  7. When middle dots (cl-05) come immediately after closing brackets (cl-02), in principle, add a quarter em space before the following middle dot (see Fig. 3.13 ⑦).

  8. When opening brackets (cl-01) come immediately after middle dots (cl-05), in principle, add a quarter em space after the preceding middle dot (see Fig. 3.13 ⑦).

Examples of line adjustment with multiple opening brackets, closing brackets, commas, full stops or middle dots.
Fig. 3.13: Examples of line adjustment with multiple opening brackets, closing brackets, commas, full stops or middle dots.

The line adjustment rules shown above have been established because the default half em space before or after consecutive punctuation marks, or quarter em space before and after them, makes the line look sparse and doesn't make the line appear well-proportioned (see Fig. 3.14).

Examples of bad line composition with unadjusted spaces between multiple opening brackets, closing brackets, commas, full stops or middle dots.
Fig. 3.14: Examples of bad line composition with unadjusted spaces between multiple opening brackets, closing brackets, commas, full stops or middle dots.

(note 1)

Japanese composition is based on the design of full-width characters, but strictly following full-width based composition sometimes produces an unbalanced appearance. In such exceptional cases, the appearance of the resulting composition must be given higher priority than the full-width design principle. When and how to invoke such exceptional procedures has a direct bearing on the quality of the text layout. In other words, it is a matter of how to resolve the conflicts between the principle and the products of it.

3.1.5 Positioning of Opening Brackets at Line Head

When starting a new line with opening brackets (cl-01) there are some patterns as shown in Fig. 3.15. Note that the amount of line indent after the line feed (the first line indent of a new paragraph) is assumed to be a one em space across all the patterns.

  1. The first line indent after the line feed is set full-width (one em) and the next line after the first line break starts with no space (so-called tentsuki) (see Fig. 3.15 ①).

  2. The first line indent after the line feed is set one and a half em and the next line indent after the first line break is set to a half em (see Fig. 3.15 ②).

  3. The first line indent after the line feed is set at a half em and the next line after the first line break is set tentsuki (see Fig. 3.15 ③).

Examples of positioning of opening brackets at line head.
Fig. 3.15: Examples of positioning of opening brackets at line head.

(note 1)

Because the inherent character width of a bracket is half-width, Fig. 3.15 ① can be explained as the result of applying the principle that any line should start with no space. On the other hand, the principle represented by Fig. 3.15 ② is to assume that opening brackets should be always accompanied by the preceding half em space as if they were full-width and then apply the same principle as in Fig. 3.15 ①. JIS X 4051 adopts the principle shown in ① (the patterns shown in ② is offered as options) . The pattern shown in ③ was first invented in books such as novels, which use frequent line feeds and corner brackets in dialogues, for which the first line indent with one em space or one and a half em space (then this pattern was accepted and adopted by general books). Major Japanese publishers who deal with literature, such as Kodansha, Shinchosha, Bungei Shunju, Chuoh Kouronsha, and Chikuma Shobo, have adopted the pattern shown in ③. By contrast, Iwanami Shoten and other publishers adopted the pattern shown in ①. Because Iwanami Shoten once adopted pattern ② in vertical composition, there used to be many examples of it, but few examples of ② can be found today.

(note 2)

The first line indent of a new paragraph is full-width in principle. However, the following exceptions can be found.

  1. The most popular scheme is to set the first line indent of all new paragraphs to full-width. However, even if there is a paragraph break and the new line looks like the beginning of new paragraph, in contexts where the new line is a continuation of the preceding line, the new line is set tentsuki as shown in Fig. 3.16. (There are books such as novels which adopt full-width line indent without exception.) Similarly, in horizontal writing mode, the line indent is set tentsuki where the new line continues the preceding line of a mathematical expression connected by conjunctions such as "therefore".

    Examples of line indent followed by the preceding line with quoted text (as in dialogues).
    Fig. 3.16: Examples of line indent followed by the preceding line with quoted text (as in dialogues).
  2. When headings have no line indent, the first line indent of the first paragraph after the heading can be also set tentsuki, for cosmetic reasons. However, it is not recommended to set the first line indent to tentsuki for all paragraphs, because it would make paragraph breaks unclear.

3.1.6 Positioning of Dividing Punctuation Marks (Question Mark and Exclamation Mark) and Hyphens

The dividing punctuation marks (cl-04) (QUESTION MARK "?" and EXCLAMATION MARK "!") should be full-width, and they are typeset as follows.

  1. Basically, add no space before dividing punctuation marks (cl-04) at the end of a sentence and add a one em space after them (see Fig. 3.17). However when a closing bracket (cl-02) follows right after the dividing punctuation mark, add no space after the dividing punctuation mark and add a half em space after the closing bracket (see Fig. 3.17).

    Positioning of dividing punctuation marks (Examples in vertical writing mode).
    Fig. 3.17: Positioning of dividing punctuation marks (Examples in vertical writing mode).

    (note 1)

    Many implementations use full-width ideographic space (cl-14) for the one em space appended after dividing punctuation marks (cl-04).

    (note 2)

    No full stops (cl-06) should be appended after dividing punctuation marks (cl-04) at the end of a sentence.

    (note 3)

    There are some cases where dividing punctuation marks (cl-04) are used in the middle of a sentence, not at the end. In those cases, either add no space or a quarter em space before and after the dividing punctuation mark see Fig. 3.18).

    Examples of positioning of dividing punctuation marks in the middle of a sentence (in vertical writing mode).
    Fig. 3.18: Examples of positioning of dividing punctuation marks in the middle of a sentence (in vertical writing mode).

    (note 4)

    The details of composition rules for dividing punctuation marks (cl-04) and hyphens (cl-03) are described in Appendix B Spacing between Characters as a complete table, in accordance with the descriptions of character classes in 3.9 About Character Classes.

  2. When dividing punctuation marks (cl-04) at the end of a sentence reach the end of a line, apply the following rules (see Fig. 3.19).

    Examples of positioning of dividing punctuation marks at the end of a line (in vertical writing mode).
    Fig. 3.19: Examples of positioning of dividing punctuation marks at the end of a line (in vertical writing mode).
    1. If the line length is 13 character widths and a dividing punctuation mark (cl-04) occurs in the 12th character position, a one em space should be appended after it.

    2. If the line length is 13 character widths and a dividing punctuation mark (cl-04) occurs in the 13th character position, no space should be appended after it. In addition, do not carry over the one em space usually appended after the dividing punctuation marks to the line head of the next line; the line in this case should be set tentsuki.

The character width of hyphens (cl-03) varies according to the type of hyphen. HYPHEN "‐" should be quarter em width (i.e. one quarter of an em width), EN DASH "–" and KATAKANA-HIRAGANA DOUBLE HYPHEN "゠" should be half-width (a half em width), WAVE DASH "〜" should be full-width. Basically there should be no space before and after hyphens (cl-03). However, a half em space should be appended, in principle, when opening brackets (cl-01) follow right after a hyphen (cl-03) and a quarter em space when middle dots (cl-05) follow a hyphen (cl-03).

3.1.7 Characters Not Starting a Line

In principle, no line should begin with closing brackets (cl-02), hyphens (cl-03), dividing punctuation marks (cl-04), middle dots (cl-05), full stops (cl-06), commas (cl-07), iteration marks (cl-09), a prolonged sound mark (cl-10), small kana (cl-11) or warichu closing brackets (cl-29) (line-start prohibition rule). Otherwise the line would have an odd appearance.

(note 1)

Not a small number of books adopt a less strict set of rules which allow IDEOGRAPHIC ITERATION MARK "々" (one of the iteration marks (cl-09)), prolonged sound mark (cl-10) and small kana (cl-11) to start a line. There is another method whereby IDEOGRAPHIC ITERATION MARK "々" is replaced by a kanji character when it would otherwise be set at the head of a line. For example, 家 (at the end of a line) + 々 (at the head of the next line) will be changed to 家 (at the end of a line) + 家 (at the head of the next line).

(note 2)

There is yet another less strict rule that allows KATAKANA MIDDLE DOT "・" to start a line.

(note 3)

In the layout of newspaper text, in addition to the symbols above, dividing punctuation marks (cl-04) (QUESTION MARK "?" and EXCLAMATION MARK "!") are allowed to start a line. This is due to the fact that the line lengths are shorter in newspapers. When the line is very short, there are fewer opportunities for inter-character space adjustment, which makes it difficult to preserve the number of characters per line. It is thought that this is why the less strict set of line head wrapping rules was adopted in newspaper text layout.

(note 4)

The details of the line-start prohibition rules and line-end prohibition rules, including the relaxations specified above, are described in Appendix B Spacing between Characters as a complete table, in accordance with the description of character classes in 3.9 About Character Classes. The line-start prohibition rules and line-end prohibition rules can be considered as Appendix B Spacing between Characters. The details of these rules are also described in Appendix C Possibilities for Line-breaking between Characters. Furthermore, line-start prohibition rules and line-end prohibition rules have several variations, so four different levels of character classes are allowed at the line-start and line-end in Appendix C Possibilities for Line-breaking between Characters C.3 Addendum.

3.1.8 Characters Not Ending a Line

No line should end with opening brackets (cl-01) or warichu opening brackets (cl-28) (line-end prohibition rules). Otherwise the line would have an odd appearance.

(note 1)

The process of formatting lines to avoid non-starter characters at the line head, non-ending characters at the line end, spaces before and/or after inseparable characters, line breaking before and/or after unbreakable characters, etc., is generally called kinsokushori.

3.1.9 Positioning of Closing Brackets, Full Stops, Commas and Middle Dots at Line End

In principle, closing brackets (cl-02), commas (cl-07) or full stops (cl-06) at the line end have a half em space after them (see Fig. 3.20). This half em space can be deleted for line adjustment (for more about line adjustment, see 3.8 Line Adjustment). However, the possibilities are only half em space or solid. Other spaces, such as a quarter em space should not be used. In principle, the middle dot (cl-05) character at the line end also has a quarter em space before and after, and is handled like a full-width character (see Fig. 3.20). This quarter em space can also be deleted for line adjustment, namely middle dots (cl-05) can be set solid before and after (about line adjustment, see 3.8 Line Adjustment). However, in this case also, the only possibilities are quarter em space or solid setting. Other intermediate-sized spacing should not be used.

Example of handling closing brackets, full stops, commas and middle dots at the line end like full-width characters.
Fig. 3.20: Example of handling closing brackets, full stops, commas and middle dots at the line end like full-width characters.

(note 1)

With regard to closing brackets (cl-02), full stops (cl-06), commas (cl-07) and middle dots (cl-05) at line end, the following processing is defined in JIS X 4051 (see Fig. 3.21).

full stops (cl-06)

After full stops (cl-06), there must be a half em space, including at the line end. This half em space must not be a target for reduction during line adjustment.

commas (cl-07)

After commas (cl-07),solid setting is applied.

closing brackets (cl-02)

After closing brackets (cl-02), solid setting is applied.

middle dots (cl-05)

In principal, before middle dots (cl-05) there is a quarter em space, and after middle dots (cl-05) solid setting is applied.

Example of handling closing brackets, full stops, commas and middle dots at the line end in JIS X 4051.
Fig. 3.21: Example of handling closing brackets, full stops, commas and middle dots at the line end in JIS X 4051.

(note 2)

In the