SMS Ack code again

I had previously posted about the text ack codes
The change from alphanumeric to 6 numeric digits has it made it slightly easier but our clients continue to ask can they not reply with their own unique user code (same reply code for every SMS that user receives) or simply “Ok” or “Ack”

Sorry, not gonna happen. It needs to be unique so it can be mapped back to one or more alarm events that the message is for.