1、 Reference number ISO/IEC TR 24754-2:2011(E) ISO/IEC 2011TECHNICAL REPORT ISO/IEC TR 24754-2 First edition 2011-10-15Information technology Document description and processing languages Minimum requirements for specifying document rendering systems Part 2: Formatting specifications for document rend
2、ering systems Technologies de linformation Description des documents et langages de traitement Exigences minimales pour spcifier les systmes de conversion de documents Partie 2: Spcifications de formatage pour les systmes de conversion de documents ISO/IEC TR 24754-2:2011(E) COPYRIGHT PROTECTED DOCU
3、MENT ISO/IEC 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member
4、body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO/IEC 2011 All rights reservedISO/IEC TR 24754-2:2011(E) ISO/IEC 2011 All rights reserved ii
5、iContents Page Foreword . v Introduction vi 1 Scope 1 2 Normative references 1 3 Terms and definitions . 2 4 General properties of the formatting specification 2 4.1 Supported output device 2 4.2 Dimension specifications . 2 4.3 Mockups . 2 4.4 Supported document formats 2 4.5 Supported style langua
6、ges 3 4.6 Rendering media dimension 3 4.7 Colour support . 3 4.8 Dynamic content generation 3 4.8.1 Generated content . 4 4.8.2 Sourced content 4 4.8.3 Example documentation . 4 4.9 Supported coded character sets and encoding schemes 6 4.10 Composition of combined characters . 6 4.11 Directionality
7、of text 6 4.12 Rendering of white-space characters . 6 4.13 Font substitution . 6 4.14 Font-resource portability 7 4.15 Embedding of non-standard characters and glyphs . 7 5 Description of pagination and rendering of page layout 7 5.1 Pages and geometry . 7 5.1.1 Page dimensions . 8 5.1.2 Horizontal
8、 page margins 8 5.1.3 Vertical page margins . 9 5.1.4 Vertical body margins . 9 5.1.5 Header and footer extents 9 5.2 Column geometry and layout grid . 9 6 Layout independent formatting . 9 6.1 Absolutely-positioned and out-of-line constructs . 10 6.2 Impacts on flow margins 10 6.3 Floats 10 6.4 Not
9、es . 11 6.4.1 Footnotes . 11 6.4.2 Side notes 11 6.4.3 End notes . 11 6.4.4 Flowed notes 11 6.4.5 Interline notes 11 6.4.6 Ruby annotations 11 7 Tables . 12 7.1 Traditional table layouts . 12 7.2 Serpentine lists in tables 12 8 Lists 13 8.1 List item dimensions . 14 ISO/IEC TR 24754-2:2011(E) iv ISO
10、/IEC 2011 All rights reserved8.2 List item identification .14 9 Block formatting 15 9.1 Blocks .15 9.2 Gaps in the flow .15 9.3 Keeps and breaks 16 9.4 Widows and orphans .17 10 Decoration 17 10.1 Graphics .17 10.2 Leaders and rules 17 11 Character-level processing .17 11.1 Hyphenation and breaks .1
11、7 11.2 Fonts, styles and leading 17 11.3 Bidirectionality of character flow .18 12 Navigational aids .18 12.1 Headers, footers and headings 18 12.1.1 Page header and footer content .19 12.1.2 Section headings .20 12.2 Tables of content .20 12.3 Bookmarks .22 12.4 Indexes 22 12.5 Linking 22 Bibliogra
12、phy 24 ISO/IEC TR 24754-2:2011(E) ISO/IEC 2011 All rights reserved vForeword ISO (the International Organization for Standardization) and IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of ISO or IEC part
13、icipate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations, government
14、al and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
15、 The main task of the joint technical committee is to prepare International Standards. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodi
16、es casting a vote. In exceptional circumstances, when the joint technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for example), it may decide to publish a Technical Report. A Technical Report is entirely
17、 informative in nature and shall be subject to review every five years in the same manner as an International Standard. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO and IEC shall not be held responsible for identifying any
18、or all such patent rights. ISO/IEC TR 24754-2 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 34, Document description and processing languages. ISO/IEC 24754 consists of the following parts, under the general title Information technology Document des
19、cription and processing languages Minimum requirements for specifying document rendering systems: Part 1: Feature specifications for document rendering systems Part 2: Formatting specifications for document rendering systems Technical Report ISO/IEC TR 24754-2:2011(E) vi ISO/IEC 2011 All rights rese
20、rvedIntroduction The scope of ISO/IEC 24754-1 makes reference to a set of style specifications an originator provides to a recipient to reconstruct the presentation of a structured document. To avoid problems with presentation, the originator and recipient must negotiate the available functionality
21、in a document rendering system. Through such negotiation, the exchanged style specifications can avoid making reference to functionality not available in the document rendering system. This manages the expectations of the originator and the recipient regarding the final rendering. ISO/IEC 24754-1 pr
22、esumes the originator (the end user with the data that is to be formatted) has created the required style specifications for the recipient (the compositor writing the stylesheet or other instructions for the document rendering system) to render the document as desired. No guidelines are included in
23、ISO/IEC 24754-1 regarding the components of a formatting specification reflecting all of the style specifications suitable for specifying the use of facilities available in the document rendering system. This part of ISO/IEC 24754 provides such guidance. Utilizing the terminology of ISO/IEC 24754-1,
24、 it describes the context of use of the features listed in ISO/IEC 24754-1 so as to direct the end user in the authoring of a useful formatting specification for developers and compositors to implement. Beyond those terms specified in ISO/IEC 24754-1, this part of ISO/IEC 24754 incorporates guidelin
25、es and terminology derived from ISO/IEC 9541 (various parts), ISO/IEC 10179, and ISO/IEC TR 19758. The relationship between this part of ISO/IEC 24754 and ISO/IEC 24754-1 is depicted in Figure 1, where the end user must write a suitable formatting specification for the compositor to create the neces
26、sary stylesheet (layout instructions) for a document rendering system to produce the appropriate formatted result for the end user. Figure 1 Relationship between ISO/IEC 24754-1 and ISO/IEC TR 24754-2 TECHNICAL REPORT ISO/IEC TR 24754-2:2011(E) ISO/IEC 2011 All rights reserved 1Information technolog
27、y Document description and processing languages Minimum requirements for specifying document rendering systems Part 2: Formatting specifications for document rendering systems 1 Scope This part of ISO/IEC 24754 provides guidelines in the writing of formatting specifications targeted for document ren
28、dering systems supporting functionality described by ISO/IEC 24754-1. There is no scope of conformance constraints against which the use of these guidelines are measured. Possible user requirements for publishing layouts are unbounded. It is the users obligation to describe their formatting requirem
29、ents to be fulfilled by a developer or a compositor using a document rendering system. Using incomplete formatting specifications can delay achieving the desired rendered result. This part of ISO/IEC 24754 is a specification of questions for the writer of a formatting specification. It is assumed th
30、at the writer of a formatting specification is unaware of the needs of the stylesheet writer in meeting the needs of the specification writer. For a writer aware of such needs, this part of ISO/IEC 24754 is a useful checklist of the issues to be considered. This part of ISO/IEC 24754 outlines variou
31、s considerations users should assess when analysing their rendering expectations. Properties described by this part of ISO/IEC 24754 should be specified in sufficient detail such that a developer or compositor has the information required to engage the necessary facilities in the document rendering
32、system. This part of ISO/IEC 24754 does not presume any particular stylesheet language with which to specify layout and formatting properties. Various stylesheet languages support different degrees of functionality described herein. Not all languages can assume to offer control over the properties d
33、escribed by this part of ISO/IEC 24754, yet it behoves the user to specify as much detail as possible so as to equip the developer or compositor for their task. By knowing as many nuances of layout as desired, there are more strategies available with which to accomplish a layout as close as possible
34、 to the requirements. Many components of this part of ISO/IEC 24754 are presented to the reader as questions in the first person, so as to ask the reader to reflect on their requirements when answering the question. 2 Normative references The following referenced documents are indispensable for the
35、application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE Each of the following documents has a unique identifier that is used to cite the document in the text. Th
36、e unique identifier consists of the part of the reference up to the first comma. ISO/IEC 24754-1, Information technology Document description and processing languages Minimum requirements for specifying document rendering systems Part 1: Feature specifications for document rendering systems ISO/IEC
37、TR 24754-2:2011(E) 2 ISO/IEC 2011 All rights reserved3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO/IEC 24754-1 and the following apply. 3.1 stylesheet external style and layout specification expressing properties of document rendering NOTE Any expr
38、ession language can be used and no particular language is presumed by this part of ISO/IEC 24754. 4 General properties of the formatting specification 4.1 Supported output device A formatting specification should describe the common layout aspects and distinguish the different layout aspects between
39、 the various target media for transformation. These distinctions may be necessary based on the target audience of the content for each medium. These distinctions may be necessary based on the rendering features for each medium. Where possible, reducing the distinctions and establishing common layout
40、 aspects between media for the same audience may promote both consistency in presentation and commonality in development of the stylesheet. 4.2 Dimension specifications All dimensions, extents, sizes and spacing values specified in the document should use units of measure appropriate to their applic
41、ation. For example page sizes, margins and large areas are often specified in imperial or SI units. Font sizes, line sizes and smaller areas are often specified in typographic units such as points (rounded to 1/72nd of an inch) and picas (12 points). One should avoid using device pixels in any lengt
42、h specification as this varies based on the choice of document rendering system properties and final form resolution. 4.3 Mockups A mockup layout illustrating the expected result using representative data is a useful guideline in the interpretation of formal formatting specifications. Nevertheless,
43、one should not rely solely on a mockup to convey all the nuances that would be better described in formal prose. Depending on the technology used to create the mockup, the compositor may be able to easily inspect layout nuances in the properties of the formatted sample. For example, hand-writing XSL
44、-FO to create the mockup, or using a desktop publishing application to compose a sample. 4.4 Supported document formats A formatting specification should describe in detail the document format and vocabulary being used to express the source content being processed by the stylesheet. In particular, w
45、hen using XML as the source document format, all details of the XML vocabulary should be well explained. When using a generic XML vocabulary it may be necessary to document conventions of use (and, more importantly, to diligently follow such conventions when composing the source documents) such that
46、 the rendering intent can be properly inferred. ISO/IEC TR 24754-2:2011(E) ISO/IEC 2011 All rights reserved 34.5 Supported style languages While in theory a formatting specification should purely be reflecting the intent of the user for rendering, there may be pragmatic or practical limitations impo
47、sed by the style language used with the document rendering system. Recognizing this, it is still in the best interests of all parties for users to express their full intent for formatting, documenting all of their expectations in the result. Developers and compositors can then interpret these requir
48、ements to choose either the appropriate style language to use, or at best the most appropriate features of the available style languages from which to choose. 4.6 Rendering media dimension A formatting specification for paged layout should describe the expected media dimensions such as A4 (210mm by
49、297mm), US Letter (8.5in by 11in), another internationally accepted dimension by its name, or a custom dimension that may be necessary. The image area is typically bound within the media dimensions using margins but for the requirement of supporting bleeds (i.e. content beyond the physical page cutting dimensions; e.g. coloured thumb indexes with or without cut indentations) may be specified to be larger than the media dimension. The paper placement (vertical/portrait or horizontal/landscape) should be specified so
