text: **DocExComment_BeginStructNode**
  
  The**DocExComment_BeginStructNode**structure marks the start of a document 
  
  structure node. Structure nodes serve one of two possible purposes: 
  
  Structure nodes can identify the type of content they contain and specify the 
  
  hierarchical relationship between that content and other content in the document. 
  
  Structure nodes can specify alternate text for elements in the document. 
  
  If the**fContentNode**member has a**true**value, the**DocExComment_BeginStructNode**is 
  
  followed later in the document by a**DocExComment_EndStructNode**. The 
  
  **DocExComment_EndStructNode**marks the end of the content that is wrapped by the 
  
  information in the**DocExComment_BeginStructNode**. 