The development that led to RFC1893 was known as "Notary". The drafts had
names like  "notary-mime-delivery-07", the  thing was generally  known to
the people who  run mail systems as  "notary" and it was just  a draft at
the time LISTSERV added support for it (1893 didn't exist, etc). Now that
it  is a  standard, I  should probably  replace this  word with  "DSN" or
"RFC1893". I have no idea why the working group chose this name.
 
  Eric