A group identifier represents an association between each of a number of different abbreviated namespace identifiers with a corresponding hierarchical namespace (e.g., an XML namespace). A hierarchically-structured document (e.g., an XML document) is accessed by a computing system that determines that...http://www.google.com.au/patents/US6993714?utm_source=gb-gplus-sharePatent US6993714 - Grouping and nesting hierarchical namespaces
