Audit Trail 2011
The PS_11 database has an audit trail to document changes to any field in the database.
This is a process that is invisible to the user. It is attached to fields in certain layouts (all non-tabled layouts that allow data entry). The UUID of a record is sent to the auditTrail table along with the name of the field, the old contents, the new contents, the user, and the date and time.
The audit trail can be viewed from any field by clicking into the field and select Show history of this field. A new window will pop up showing all changes to that field.
There is more detailed information in the Dev Manual (Audit Trail).