4123aafc__Oracle_Text_Indexing_Elements__Description
[Section Group Preference] AUTO_SECTION_GROUP [Description] 
Use this group type to automatically create a zone section for each start-tag/end-tag pair in an XML document. The section names derived from XML tags are case sensitive as in XML. Attribute sections are created automatically for XML tags that have attributes. Attribute sections are named in the form tag@attribute. Stop sections, empty tags, processing instructions, and comments are not indexed. The following limitations apply to automatic section groups: You cannot add zone, field, or special sections to an automatic section group. You can define a stop section that applies only to one particular type; that is, if you have two different XML DTDs, both of which use a tag called FOO, you can define (TYPE1)FOO to be stopped, but(TYPE2)FOO to not be stopped. The length of the indexed tags, including prefix and namespace, cannot exceed 64 characters. Tags longer than this are not indexed.
2 Oracle Text Indexing Elements