DocumentID: ECMA-376/Part5/9.2.3 Title: ECMA-376, Part5: 9.2.3 Fallback Element Extracted-From: ECMA-376 Office Open XML File Formats, 1st Edition / December 2006 Warning: Coverted to HTML format by a script known to have bugs
If no Choice element can be selected, markup consumers shall use the content provided in a Fallback element, if present. If no Choice element can be selected and no Fallback element is provided, the document content is processed as if the AlternateContent element were absent.
Fallback elements can include the attributes Ignorable, MustUnderstand, ProcessContent, PreserveElements, and PreserveAttributes described in this specification. These attributes shall be prefixed when on a Fallback element. A markup consumer shall generate an error if it encounters a Fallback element having any unprefixed attribute name. [Note: A namespace declaration is not considered to be an unprefixed attribute name. end note]
Fallback elements might have ignored attributes. Markup consumers shall not generate an error when encountering such attributes. However, markup consumers shall generate an error when encountering an attribute of the Fallback element that belongs to a namespace that is neither understood nor ignorable.
Markup producers shall not generate Fallback element s that have the xml:lang or xml:space attributes. Markup consumers shall generate an error if they encounter the xml:lang or xml:space attributes on a Fallback element, regardless of whether the element is preceded by a selected Choice element.