Group Parameters
================

   Gnus stores all information on a group in a list that is usually
known as the "group info".  This list has from three to six elements.
Here's an example info.

     ("nnml:mail.ding" 3 ((1 . 232) 244 (256 . 270)) ((tick 246 249))
                       (nnml "private") ((to-address . "ding@ifi.uio.no")))

   The first element is the "group name", as Gnus knows the group,
anyway.  The second element is the "subscription level", which normally
is a small integer.  The third element is a list of ranges of read
articles.  The fourth element is a list of lists of article marks of
various kinds.  The fifth element is the select method (or virtual
server, if you like).  The sixth element is a list of "group
parameters", which is what this section is about.

   Any of the last three elements may be missing if they are not
required.  In fact, the vast majority of groups will normally only have
the first three elements, which saves quite a lot of cons cells.

   The group parameters store information local to a particular group:

`to-address'
     If the group parameter list contains an element that looks like
     `(to-address .  "some@where.com")', that address will be used by
     the backend when doing followups and posts.  This is primarily
     useful in mail groups that represent closed mailing lists--mailing
     lists where it's expected that everybody that writes to the
     mailing list is subscribed to it.  Since using this parameter
     ensures that the mail only goes to the mailing list itself, it
     means that members won't receive two copies of your followups.

     Using `to-address' will actually work whether the group is foreign
     or not.  Let's say there's a group on the server that is called
     `fa.4ad-l'.  This is a real newsgroup, but the server has gotten
     the articles from a mail-to-news gateway.  Posting directly to this
     group is therefore impossible--you have to send mail to the mailing
     list address instead.

`to-list'
     If the group parameter list has an element that looks like
     `(to-list . "some@where.com")', that address will be used when
     doing a `a' in any group.  It is totally ignored when doing a
     followup--except that if it is present in a news group, you'll get
     mail group semantics when doing `f'.

`broken-reply-to'
     Elements like `(broken-reply-to . t)' signals that `Reply-To'
     headers in this group are to be ignored.  This can be useful if
     you're reading a mailing list group where the listserv has inserted
     `Reply-To' headers that point back to the listserv itself.  This is
     broken behavior.  So there!

`to-group'
     If the group parameter list contains an element like `(to-group .
     "some.group.name")', all posts will be sent to that group.

`auto-expire'
     If this symbol is present in the group parameter list, all
     articles that are read will be marked as expirable.  For an
     alternative approach, see Expiring Mail..

`total-expire'
     If this symbol is present, all read articles will be put through
     the expiry process, even if they are not marked as expirable.  Use
     with caution.

`expiry-wait'
     If the group parameter has an element that looks like `(expiry-wait
     . 10)', this value will override any `nnmail-expiry-wait' and
     `nnmail-expiry-wait-function' when expiring expirable messages.
     The value can either be a number of days (not necessarily an
     integer) or the symbols `never' or `immediate'.

`score-file'
     Elements that look like `(score-file . "file")' will make `file'
     into the current score file for the group in question.  This means
     that all score commands you issue will end up in that file.

`admin-address'
     When unsubscribing to a mailing list you should never send the
     unsubscription notice to the mailing list itself.  Instead, you'd
     send messages to the administrative address.  This parameter
     allows you to put the admin address somewhere convenient.

`comment'
     This parameter allows you to enter a arbitrary comment on the
     group.

`(VARIABLE FORM)'
     You can use the group parameters to set variables local to the
     group you are entering.  Say you want to turn threading off in
     `news.answers'.  You'd then put `(gnus-show-threads nil)' in the
     group parameters of that group.  `gnus-show-threads' will be made
     into a local variable in the summary buffer you enter, and the form
     `nil' will be `eval'ed there.

     This can also be used as a group-specific hook function, if you'd
     like.  If you want to hear a beep when you enter the group
     `alt.binaries.pictures.furniture', you could put something like
     `(dummy-variable (ding))' in the parameters of that group.
     `dummy-variable' will be set to the result of the `(ding)' form,
     but who cares?

   If you want to change the group info you can use the `G E' command
to enter a buffer where you can edit it.

   You usually don't want to edit the entire group info, so you'd be
better off using the `G p' command to just edit the group parameters.