This element contains rules for ITS information, to be used in documents. An element to describe namespace URIs and prefixes within XPath expressions in selector attributes. A rule to express ITS information and select parts of a document respectively. documentRule is to be used in a in rule context only. A rule to express ITS information about the element declaration to which the schemaRule element is attached as schema annotation. An element used as a general container for ITS data category attributes.