Partial X12 850 Document sent by affliliate

Is there a way to read a partial 850 EDI document in X12 format that does not have the Interchange or Functional Group Header and Trailer wrapper tags? The affiliate is stripping out those tags before sending us the 850 PO Document. We do not get the ISA, IEA, GS or GE tags. The document is read correctly with those tags. I was wondering if there is a way to tell the grammar those tags are not present and keep parsing the file.

Thanks.....Mike

Start by locating the X12 grammar and parser entry point that handles the ISA, IEA, GS, and GE wrapper tags. Check how parsing behaves when those tags are absent, then verify that a partial 850 purchase-order document can be read successfully without the wrappers.

Written by the indexing model from the issue text.