Account Derivation Rule Sources

 This question is more of a generic SLA question though the immediate need is in the Cost Management arena.  Specifically, I am looking for a source that maps form data fields to Account Derivation Rules sources. 

As an example, through trial and error testing, I determined that the ADR source Transaction Distribution Account mapped to the Account field on the Miscellaneous Receipt/Issue form (not a difficult guess but since Sources are rarely named the same as the field name on the form and they often can be used for multiple purposes, guessing is all that I have now).

Now when I entered an account alias receipt, I expected that the same source would work since the form is essentially the same.  It did not.