Section title: Requests for Interpretation
Clarification is required on the difference between IK4-03 error codes "1" and "I9" in 999 Implementation acknowledgements

My question is more to get additional clarification on the Implementation Data Element Syntax Error Code (IK4-03 element in 5010X231 Implementation Acknowledgement - 999 specs).
We have a code value "1" - which has a definition of "Required Data Element Missing."
We also have a code value "I9" - which has a definition of "Implementation Dependent Data Element missing."

We need to understand the differences between the two. We always generate 999s with IK4-03 as '1' when a data element is missing. However, some of our customers have reported issues expecting the value to be I9. I cannot find any online materials or further explanation within the X12/Glass that explains this better.

Need to understand what scenarios should result in IK4-03 to be set as "1" vs "I9" when generating 999 Implementation acknowledgments.

RFI Response

Code value "1" refers to the EDI Standard and is sent when a mandatory data element is not present in a segment.
The code values that begin with an "I" indicate the error is reported against the instructions in an implementation guide. Code value "I9" indicates that an element is missing that became required based on a situational rule or other content in the segment.  For example, many NM104 elements contain a situational rule stating that NM104 is required if NM102=1. Consequently, if NM102 =1 and NM104 is empty, code value "I9" in IK4-03 is the appropriate response.