rc>     Where does it get the original 'starting' serialno from? Is 
rc> it stored in a file or generated each time the editor is run?

The latter, based on the system time.  There may be problems if the
system time is moved backwards (eg. put back an hour after daylight
savings), but this should be no less a problem than how Msged originally
generated the MSGID serialno.

I might use a file to store the last serialno generated and use that as
the starting serialno when Msged is next run.  Not a real concern
though; it works as-is.

regards
andrew

--- Msgedsq/2 3.04