Hi William,
If you are referring to posting adjustments against AP transactions, or journal entries in AL, then both of these types of changes are written to a posting journal file which can be kept for the audit trail. Neither of these functions attach a 'user name' along with the entries.
If you are referring to editing Account History in Ledger, then there is no audit trail.
All Adagio applications (versions 6.8A and later) have security by user group and function, so if your concern is to prevent certain users from performing functions that will adversely affect the data, then you can set up security to do just that.
Regards,