XML Schema Complete Reference, The

7.7. The documentation Element

Only an annotation element can contain a documentation element. The value of a documentation element is human-readable text that describes the element that encloses the annotation. The content, in an XML instance, of a documentation element is not constrained. Listing 7.3 contains an annotation element, which encloses several appinfo elements. The following is a suitable excerpt that demonstrates a documentation element with mixed content:

<xsd:documentation xml:lang="en"> 
    Developer Note:  Someone should probably come up 
    with a way to actually validate PMBs.  In fact, 
    it would be great if we could validate 
    every <pmb/> and <POBox/> element. 
</xsd:documentation> 

An element that contains mixed content, as just demonstrated, ...