SIST ISO 24613-1:2024

International
Standard
ISO 24613-1
Second edition
Language resource management —
2024-01
Lexical markup framework (LMF) —
Part 1:
Core model
Gestion des ressources linguistiques — Cadre de balisage lexical
(LMF) —
Partie 1: Modèle de base
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Key standards used by LMF . 3
4.1 Unicode .3
4.2 Language coding .3
4.3 Script coding .3
4.4 Unified modelling language .3
5 The LMF model . 3
5.1 General .3
5.2 Class inheritance and data category selection procedures .4
5.2.1 Class inheritance .4
5.2.2 LMF attributes .4
5.2.3 Data category selection (DCS) .4
5.2.4 User-defined data categories . .4
5.3 LMF core package .4
5.3.1 General .4
5.3.2 LexicalResource class .5
5.3.3 GlobalInformation class .5
5.3.4 Lexicon class .6
5.3.5 LexiconInformation class .6
5.3.6 LexicalEntry class .6
5.3.7 Form class .6
5.3.8 OrthographicRepresentation class .6
5.3.9 GrammaticalInformation class .6
5.3.10 Sense class .6
5.3.11 Definition class .7
5.4 Cross reference (CrossREF) model .7
5.4.1 General .7
5.4.2 CrossREF class .7
5.4.3 CrossREFConstraint class .7
5.5 Methods for data category selection and subclass creation .7
5.5.1 General .7
5.5.2 Generalization.7
5.5.3 Object instantiation .8
5.5.4 Design choices.8
5.5.5 Data categories for orthographic representation .8
5.5.6 Principles for model simplification .9
5.6 LMF extension use .9
5.6.1 General .9
5.6.2 Lexicon comparison.10
Annex A (informative) Data category examples .11
Bibliography . 14

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 37, Language and terminology, Subcommittee
SC 4, Language resource management.
This second edition cancels and replaces the first edition (ISO 24613-1:2019), which has been technically
revised.
The main changes are as follows:
— several changes have been made to Figure 1 “LMF core package”, as follows:
— the OrthographicRepresentation class associations with the Form and Definition classes previously
had a cardinality of 1 to 1, which did not correctly represent the intent of the UML model; the revision
of the cardinality to 1 to 0.* in each case now provides a correct model;
— the type: intern/extern attribute-value pair is no longer included in the CrossREF class since it
described linking processes relevant for implementations, not associations relevant for a metamodel;
— the full names relationship values in the CrossREF class, “synonym/composition” replace the
abbreviations, “syn/compo”;
— the class names in Figure 1 are now harmonized with the LMF style;
— relevant information has been moved from the tables in ISO 24613-2:2020 to Table A.1, meaning that the
latter now contains more complete examples of values and attributes allocated to classes first introduced
in this document.
A list of all parts in the ISO 24613 series can be found on the ISO website.
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
Optimizing the production, maintenance and extension of electronic lexical resources is one of the crucial
aspects impacting human language technologies (HLTs) in general and natural language processing (NLP) in
particular, as well as human-oriented translation technologies. A second crucial aspect involves optimizing
the process leading to their integration in applications. Lexical markup framework (LMF) is an abstract
metamodel that provides a common, standardized framework for the construction of computational
lexicons. LMF ensures the encoding of linguistic information in a way that enables reusability in different
applications and for different tasks. LMF provides a common, shared representation of lexical instances,
including morphological, syntactic and semantic aspects.
The goals of LMF are:
— to provide
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