lotus-notes
concurrency
Documents in conflict have the $Conflict field on them. Forms can have the $ConflictAction set on them, when setting this to 3 (Merge/No Conflicts) then Lotus Notes will attempt to merge the document at a field level (Every field in fact has a LastModifiedDate).
Not replicating for a long time is the bane of all evil.
overview
For a brief overview of what lotus notes is, check out http://www.nsftools.com/misc/WhatIsNotes.htm