Input Messaging Accountability Data (IMAD) tag

[chris-griffin]

We currently fill the Input Messaging Accountability Data (IMAD) tag during file generation in this library. However, we override this field in downstream repos to make it blank (but still include the '1520' tag).

The standards do not make it clear how the IMAD tag should be treated during file generation. However, there are several references that seem to imply the IMAD content is always generated by the actual Fedwire system. There is a similar convention in the ACH world.

E.g.

The Input Message Accountability Data (IMAD) number assigned by the Fedwire system

https://download.eftps.com/Financial_Institution_Handbook.pdf

Input Messaging Accountability Data: A combination of a date, source identifier, and sequence number assigned to a Fedwire message when it is processed by the Federal Reserve Bank Funds Transfer application.

https://www.fiscal.treasury.gov/registry/TreasuryFiscalService/2443/index.html

We need to determine if:

(1) we should include the '1520' tag but with no content (a deviation from the treatment of no content tags elsewhere in the standard);
(2) we should not include the '1520' tag at all; or
(3) continue to generate placeholder content for the '1520' tag

I reached out the the contact listed as the 'Data Steward' on https://www.fiscal.treasury.gov/registry/TreasuryFiscalService/2443/index.html for clarification