ISO/DTS 32009

• Abstract:

  This document specifies how to extend the ISO 32000-2:2020 specification by adding support for multi-lingual text strings for all text strings defined in PDF. This document does not specify the following: — specific processes for converting paper or electronic documents to the PDF file format; — specific technical design, user interface implementation, or operational details of rendering; — specific physical methods of storing these documents such as media and storage conditions; — methods for validating the conformance of PDF files or PDF processors; — required computer hardware and/or operating system

• Status: Not Published
• ICS: 35.240.30 - IT applications in information, documentation and publishing
• ICS: 37.100.99 - Other standards related to graphic technology
• Technical Committee: ISO/TC 171/SC 2 - Document file formats, EDMS systems and authenticity of information
• Drafting Committee: ISO/TC 171/SC 2 - Document file formats, EDMS systems and authenticity of information
• Current Stage: 5020 - FDIS ballot initiated: 2 months. Proof sent to secretariat
• Start Date: 18-Sep-2026
• Completion Date: 18-Sep-2026

ISO/DTS 32009 is an ISO draft technical specification for Document management - Portable Document Format - Extension to support language identification in multilingual strings in ISO 32000-2 (PDF 2.0). It specifies an extension to ISO 32000-2:2020 for adding language information to multilingual text strings and text streams in PDF. The document is aimed at developers and implementers of software that creates, consumes, or processes PDF files.

What does ISO/DTS 32009 specify?

ISO/DTS 32009 specifies how to extend ISO 32000-2:2020 so that PDF can carry multilingual text objects for all text strings defined in PDF. In practice, that lets a PDF encode the language of text that mixes languages inside a single string or stream, instead of relying only on older language-marking methods.

The scope is limited to the PDF extension itself. It excludes document conversion processes, rendering design or user interface details, storage media and conditions, conformance validation methods, and hardware or operating system requirements.

The document is organized into Scope, Normative references, Terms and definitions, Notation, Extension schema details, and Multilingual strings, followed by a bibliography.

What are the key requirements of ISO/DTS 32009?

ISO/DTS 32009 adds a catalog-level extension mechanism and a defined XML-based way to describe language inside PDF text objects. The main practical effect is that a producer can keep the original PDF text string and add a parallel language-aware form for the same content.

• Clause 5 - Extension schema details: PDF documents using these enhancements shall include an extensions dictionary in the document catalog dictionary, with a developer extensions dictionary under the ISO_ prefix. This is the registration hook that tells a processor the file uses this extension.
• Clause 5 - Required extension entries: The developer extensions dictionary uses a base version of 2.0 and identifies the extension level, revision, type, and URL. In practice, these entries let software recognize the extension and associate it with the ISO specification.
• Clause 6.1 - Motivation and context: ISO/DTS 32009 explains that existing PDF language mechanisms do not handle mixed-language strings well, especially where language changes inside one string. That matters when creating bookmarks, alternative descriptions, or other text that a reader may see in more than one language.
• Clause 6.2.2 - Multilingual text objects: A multilingual text object shall be well-formed XML with a single body element, and only p and span elements may appear inside it. Language is assigned with the unqualified lang attribute, and the XML encoding shall be UTF-8.
• Clause 6.2.2 - Content restrictions: Namespaces, DOCTYPE declarations, processing instructions beyond an initial XML declaration, and all attributes other than lang are not used. That keeps the object focused on text and language, not layout or other XML features.
• Clause 6.2.3 - Single text strings and streams: For any entry that accepts a text string or stream, a corresponding multilingual text object may be added with the same key name plus Lang. The multilingual text content shall match the original text, apart from whitespace and null characters.
• Clause 6.2.4 - Arrays of text strings: Where a PDF entry permits an array of text strings, a matching array of multilingual text objects may be supplied under a key ending in Lang. The array lengths shall match, and each position is either a multilingual text object or a null entry.
• Clause 6.2.2 and 6.2.3 - Practical behavior: The multilingual object acts like a regular PDF string or stream for handling and encryption, but it carries explicit language information for each text segment. That helps downstream workflows that reuse, extract, or process text, even when some APIs do not understand the language markup.

What terms does ISO/DTS 32009 define?

ISO/DTS 32009 defines a small set of terms that frame how the extension works.

• processor - software that can read and process conforming files.
• interactive processor - a processor that requires or allows human interaction with document content during processing, such as a file viewing tool.
• rich text object - a text string or text stream containing rich text.
• multilingual text object - a rich text object restricted to text and language control, used to carry language-marked content inside PDF.

Who uses ISO/DTS 32009?

ISO/DTS 32009 is intended for developers and implementers of software that creates, consumes, or processes PDF files. It is relevant to PDF tool vendors, format engineers, and teams building viewers, editors, conversion tools, and extraction workflows that need to preserve language information in mixed-language text.

It is especially useful where a PDF contains language-sensitive content such as outline items, alternative descriptions, or other text strings that may switch language inside one object. For those users, the standard provides a controlled way to pair the visible text with explicit language identification.

Which standards are used with ISO/DTS 32009?

ISO/DTS 32009 is used together with ISO 32000-2:2020, which supplies the base PDF 2.0 model that this document extends. It also refers to Adobe XML Forms Architecture, Adobe XML Forms Architecture (XFA) Specification, version 3.3 (January 2012), which provides the rich text and language-control concepts reused for multilingual text objects.

The text also refers to ISO 3166-1:2020 and IETF RFC 5646 when explaining the older language-tag mechanism that this document improves upon. Those references help explain why the new approach is needed for multilingual strings.

What does the ISO/DTS 32009 document contain?

ISO/DTS 32009 contains notation rules for reading PDF syntax in the document, including how operators, keys, token characters, and Unicode characters are shown. It also contains one extension-schema table that defines the PDF catalog entries needed to declare the extension.

Clause 6 gives the technical model for multilingual strings, including the general background, the XML structure of multilingual text objects, and the rules for extending single text-string entries and arrays of text strings. The document also includes examples of outline dictionaries with mixed-language titles, showing how the Lang companion entries are used in practice.

FINAL DRAFT
Technical
Specification
ISO/TC 171/SC 2
Document management — Portable
Secretariat: ANSI
Document Format — Extension to
Voting begins on:
support language identification in
2026-09-18
multilingual strings in ISO 32000-2
Voting terminates on:
(PDF 2.0)
2026-11-13
Gestion des documents — Format de document portable —
Extension pour la prise en charge de l'identification des langues
dans les chaînes multilingues dans l'ISO 32000-2 (PDF 2.0)
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
FINAL DRAFT
Technical
Specification
ISO/TC 171/SC 2
Document management — Portable
Secretariat: ANSI
Document Format — Extension to
Voting begins on:
support language identification in
multilingual strings in ISO 32000-2
Voting terminates on:
(PDF 2.0)
Gestion des documents — Format de document portable —
Extension pour la prise en charge de l'identification des langues
dans les chaînes multilingues dans l'ISO 32000-2 (PDF 2.0)
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2026
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Notation . 2
5 Extension schema details . 2
6 Multilingual strings . 2
6.1 General .2
6.2 Extending multilingual string support .3
6.2.1 General .3
6.2.2 Multilingual text objects .3
6.2.3 Extending entries for text strings .4
6.2.4 Extending entries for arrays of text strings.5
Bibliography . 6

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 171, Document management applications,
Subcommittee SC 2, Document file formats, EDMS systems and authenticity of information.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
This document specifies a method for encoding text strings or text streams using Unicode that are found
outside of page content. These text strings and streams are generally designed to be human-readable and
hence have an associated language. While PDF includes methods for indicating the language of these strings,
this mechanism does not adequately support all scenarios and complexities, particularly when it comes to
multilingual strings where a single string contains multiple languages. Example uses for these multilingual
text objects include alternative descriptions and text in outline items (bookmarks), where the language can
change within the string or differ from that specified elsewhere in the document.
NOTE This document does not specify a method for supplying alternative text in multiple languages. Instead, it
focuses on a method for specifying the language of a single string or stream that contains text in multiple languages.
This document is an extension to ISO 32000-2:2020, defining a means of providing language identifiers
within multilingual text objects to fully specify the language for any Unicode string in a PDF.
This document is intended for developers and implementers of software that creates, consumes, or processes
PDF files.
This document is intended to be used in conjunction with ISO 32000-2.
This document uses custom notation to convey additional meaning, as specified in Clause 4.

v
FINAL DRAFT Technical Specification ISO/DTS 32009:2026(en)
Document management — Portable Document Format —
Extension to support language identification in multilingual
strings in ISO 32000-2 (PDF 2.0)
1 Scope
This document specifies how to extend ISO 32000-2:2020 by adding support for multilingual text objects for
all text strings defined in PDF.
This document does not specify the following:
— specific processes for converting paper or electronic documents to the PDF file format;
— specific technical design, user interface implementation, or operational details of rendering;
— specific physical methods of storing these documents such as media and storage conditions;
— methods for validating the conformance of PDF files or PDF processors;
— required computer hardware or operating system.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) appli
...

Reference number of working document: ISO TC 171/SC 2/WG 8 N 0000
Date: 2025-10-28
Reference number of project: ISO/DTS 32009 (draft 2025-10-28)
Committee identification: ISO/TC 171/SC 2/WG 8
Secretariat: ANSI
Date: 2026-09-04
Document management — Portable Document Format — Extension
to support language identification in multilingual strings in ISO
32000-2 (PDF 2.0)
Gestion dedes documents — Portable Document — Format de document portable — Extension pour prendrela
prise en charge l’identificationde l'identification des langues dans les chaînes multilingues dans ISOl'ISO 32000-
2 (PDF 2.0)
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication
may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,
or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO
at the address below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: + 41 22 749 01 11
Email: E-mail: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Notation . 2
5 Extension schema details . 2
6 Multilingual strings . 3
6.1 General. 3
6.2 Extending multilingual string support . 3
Bibliography . 7

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
ISO documentsdocument should be noted. This document was drafted in accordance with the editorial rules
of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawnISO draws attention to the possibility that some of the elementsimplementation of this
document may beinvolve the subjectuse of (a) patent(s). ISO takes no position concerning the evidence,
validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this
document, ISO had not received notice of (a) patent(s) which may be required to implement this document.
However, implementers are cautioned that this may not represent the latest information, which may be
obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for
identifying any or all such patent rights. Details of any patent rights identified during the development of the
document will be in the Introduction or on the ISO list of patent declarations received (see ) or both.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation onof the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO’sISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT)), see the following URL:
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 171, Document management applications,
Subcommittee SC 2, Document file formats, EDMS systems and authenticity of information.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
This document specifies a method for encoding text strings or text streams using Unicode that are found
outside of page content. These text strings and streams are generally designed to be human-readable and
hence have an associated language. While PDF includes methods for indicating the language of these strings,
this mechanism does not adequately support all scenarios and complexities, particularly when it comes to
multilingual strings where a single string contains multiple languages. Example uses for these multilingual
text objects include alternative descriptions and text in outline items (bookmarks), where the language can
change within the string or differ from that specified elsewhere in the document.
NOTE This document does not specify a method for supplying alternative text in multiple languages. Instead, it
focuses on a method for specifying the language of a single string or stream that contains text in multiple languages.
This document is an extension to ,ISO 32000-2:2020, defining a means of providing language identifiers within
multilingual text objects to fully specify the language for any Unicode string in a PDF.
This document is intended for developers and implementers of software that creates, consumes, or processes
PDF files.
This document is intended to be used in conjunction with ISO 32000-2.
This document uses custom notation to convey additional meaning, as specified in Claude Clause 4.
Field Code Changed
v
Document management — Portable Document Format — Extension to
support language identification in multilingual strings in ISO 32000-2
(PDF 2.0)
1 1 Scope
This document specifies how to extend ISO 32000-2:2020 by adding support for multilingual text objects for
all text strings defined in PDF.
This document does not specify the following:
— — specific processes for converting paper or electronic documents to the PDF file format;
— — specific technical design, user interface implementation, or operational details of rendering;
— — specific physical methods of storing these documents such as media and storage conditions;
— — methods for validating the conformance of PDF files or PDF processors;
— — required computer hardware or operating system.
2 2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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.
ISO 32000-2:2020, Document management —  — Portable document format —  — Part 2: PDF 2.0
Adobe XML Forms Architecture, Adobe XML Forms Architecture (XFA) Specification, version 3.3 (January
2012), Adobe Systems Incorporated
3 3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— — ISO Online browsing platform: available at https://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/
3.1 3.1
processor
software application that is able to read and process conforming files
3.2
interactive processor
processor () that requires or allows human interaction with the content and other objects contained in the
document during the software’s processing phase
Note 1 to entry: A file viewing tool is an example of an interactive processor; a raster image processor is an example of a
processor that is not interactive.
3.2 3.3
rich text object
text string or text stream containing rich text
Note 1 to entry: For details on text string, see ().ISO 32000-2:2020, 7.9.2.2. For details on text stream, see .ISO 32000-
2:2020, 7.9.3. For details on rich text, see .Adobe XML Forms Architecture, Clause 5.
3.3 3.4
multilingual text object
rich text object ((3.2) restricted to text and language control
4 4 Notation
PDF operators, PDF keywords, the names of keys in PDF dictionaries, and other predefined names are written
in bold sans serif font; operands of PDF operators or values of dictionary keys are written in italic font. Some
names can also be used as values, depending on the context, and so the styling of the content will be context
specific.
EXAMPLE 1
...