> > > X-Listserver: Your list server.
> > > X-Listmanager: Blah.
> > I am somewhat lazy and like Scott Ophof's abbreviation.
> > Why not
> > X-MLM: your favorite here.
> This falls into the same category as 'X-Pmrqc' - how is someone supposed
> to know what the abbreviation 'MLM' means?
Regardless of what this line may be, I have found out it to be very useful.
A few people are writing a "global" interface to as many list management
systems as possible so that their users do not have to remember what the
syntax is for subscription (for example) for each of those systems. When these
users submit such a request, the system will first issue "help", then look for
such header lines and possibly rewrite the request to match the syntax
requirements if a certain automated list management system is recognized.
It will then record that particular reply address and classify it as one
of the known list management systems, so that next time it will not issue
Version numbers also help in functions like searching archives, or obtaining
files from archives.