Does Loop ID-1000A (Submitter Name) always have to appear before 1000B (Receiver Name), or is it valid for 1000B to appear before 1000A? Section 1.4.3.1 states, "As the 2000 level loops define the hierarchical structure, they are required to be used in the order shown in the implementation guide." The 1000A/B loops do not define the hierarchical structure in the sense that they do not contain subloops, so we are not certain whether the same rule applies. Section 2.3.1 Table 1 shows Loop ID-1000A before 1000B, but we are not clear whether that represents a formal ordering constraint.
We noticed that RFI # 1491 states, "Numerically equivalent loops can be sent in any order." Does that apply to all loops, including those at the top level of a transaction, or only to subloops? We assume the latter, since otherwise it would seem to contradict section 1.4.3.1.
We received a transaction where Loop ID-1000B appeared before 1000A and are unclear about whether it is valid or should be rejected.
Numerically equivalent loops may be sent in any order. In the scenario presented, it is allowed to have a 1000B loop appear in the data before a 1000A loop.
This issue is explicitly addressed in X12.59 (Implementation of EDI Structures-Semantic Impact), Section 6.2, Example 2 (Loop Independence).
X12.59 is available through Glass, X12's online viewer. Please see https://ecommerce.x12.org/license/glass for more information.
Related RFIs: RFI #1491: 837 'un-sequenced' subloops