text: If you look at offset 201 in the .out file, you find a BNG Structured Field (if the .out file is 
  AFP), which indicates the start of a document. 
  
  You might see Page IELs in the index file. These Page IELs are created by setting the ACIF 
  parameter INDEXOBJ=ALL. They are needed (and are required) only if the document is being 
  loaded as large object. Example 7-2 shows part of a Page IEL. 
  
  *Example 7-2 Part of a Page IEL*
  
  7 IEL Index Element 0044 D3B2A7 
   IEL Object Byte Extent Triplet (57) 
  **IEL Extent = 1342 (53E) <- LENGTH OF PAGE**
   IEL Object Byte Offset Triplet (2D) 
  **IEL byte offset = 456 (1C8) <- WHERE IT STARTS IN THE .OUT FILE**
   IEL Object Structured Field Extent Triplet (59) 
   IEL Extent = 11 (B) 
   IEL Object Structured Field Offset Triplet (58) 
   IEL Offset = 7 (7) 