ISO/IEC INTERNATIONAL STANDARD 29500-3 Fourth edition 2015-07-01 Information technology Document description and processing languages Office Open XML File Formats - Part 3: Markup Compatibility and Extensibility Technologies de I'information - Description des documents et langages de traitement-Formats de fichier"Office OpenXML"- Partie 3: Compatibilité et extensibilité du balisage Reference number ISO/IEC29500-3:2015(E) IEC @ISO/IEC2015 ISO/IEC 29500-3:2015(E) Contents Foreword.. i Introduction. 1 Scope. 2 Normative References .. Terms and Definitions 4 Notational Conventions. 5 General Description. 6 Overview MCE Elements and Attributes. 7.1 Introduction 7.2 Ignorable Attribute... 7.3 ProcessContentAttribute. 7.4 MustUnderstand Attribute . 7.5 AlternateContent Element. 10 7.6 ChoiceElement. 7.7 Fallback Element. 11 8 Application-Defined Extension Elements .13 9 Semantic Definitions and Reference Processing Model .... 15 9.1 Overview... 15 9.2 Step 1: Processing the Ignorable and ProcessContent Attributes 9.3 Step 2: Processing the AlternateContent, Choice and Fallback Elements 17 9.4 Step 3: Processing the MustUnderstand Attribute and Creating the Output Document. 18 Annex A (informative) Examples .. A.1 Syntactic Examples.. A.1.1 22 A.1.2 Ignorable Attribute: Multiple Prefixes Bound to a Namespace. A.1.3 Ignorable Attribute: Non-conformant Use . A.1.4 ProcessContentAttribute:MultiplePrefixesBoundtoaNamespace A.1.5 ProcessContent Attribute: Non-conformant Use A.1.6 MustUnderstand Attribute: Non-conformant Use A.1.7 AlternateContent Element: Future Extensibility. 24 A.2 SemanticExamples A.2.1 General..... A.2.2 Ignorable Attribute ... 24 A.2.3 Ignorable and ProcessContent Attributes.. A.2.4 Non-lgnorable and Non-Understood Namespace A.2.5 MustUnderstand Attribute ... @ISO/IEc 2015 - All rights reserved ISO/IEC 29500-3:2015(E) A.2.6 AlternateContentElement... .... 28 A.2.7 Ignorable Content Inside Application-Defined Extension Elements 29 Annex B (informative) Validation Using NVDL. Bibliography... 33 ii IS0/IEc 2015 - All rights reserved