does anybody use FinCENs list of registered MSBs without a copy of the acknowledgment letter?

No, if they are expired, I will print it but we always follow up on receiving the actual FinCEN MSB Registration Confirmation

Thanks. I was told that I could use the list- i didn't think so. I always thought that the list was for general reference for the public and should not be treated as proof of an entity's registration status. I think there was guidance issued on that but I can't find it at this moment. I really would like to find the guidance.

There is a disclaimer somewhere on the msb.gov site that says that the list is not to be considered as 100% correct and up-to-date. We always require a copy of the FinCEN acknowledgement.

Prior thread per Devsfan's comment.