A TA1 is supposed to return an acknowledgment based on checking the contents of the ISA and IEA segments. However, the existing documentation appears to contradict the scope of the validation. One of the note codes is "024 Invalid Interchange Content (e.g., Invalid GS Segment)". This note code implies the TA1 acknowledgment status is affected by the contents of the groups and transactions, not just the ISA and IEA segments.
Therefore, we need to know how to interpret note code 24 and whether or not the presence of errors outside the ISA/IEA segments affects the acknowledgment status of the TA1.
We agree with you that one can infer from the definition of the TA1 that only the ISA and IEA are in scope. X12C intends to propose a change to the standard to provide more clarity.