Is there any soluation to handle account (TAB) for input sources not defined in the rules?

Summary:

Lets say we will build a new accouting rule that reads mapping set with output item catogery, it the buisness user define a new catogery or requester used catogery that is missed in the mapping set, is there anyway to take in considration the manual entry for charge account without raising error?

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25D

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