The 329 data element stores the control number for the transaction
set in the Transaction Set Header (ST)
and Trailer (SE).
The control number must match for the header and trailer in one
transaction set. When Framework EDI, creates the transaction
set, the control number is determined by the incremental count of
transaction sets in the functional group. This is the default
value and may not be correct for the organization, so it should by
overwritten where applicable.
