+@node Web Searches
+@subsection Web Searches
+@cindex nnweb
+@cindex DejaNews
+@cindex Alta Vista
+@cindex InReference
+@cindex Usenet searches
+@cindex searching the Usenet
+
+It's, like, too neat to search the Usenet for articles that match a
+string, but it, like, totally @emph{sucks}, like, totally, to use one of
+those, like, Web browsers, and you, like, have to, rilly, like, look at
+the commercials, so, like, with Gnus you can do @emph{rad}, rilly,
+searches without having to use a browser.
+
+The @code{nnweb} backend allows an easy interface to the mighty search
+engine. You create an @code{nnweb} group, enter a search pattern, and
+then enter the group and read the articles like you would any normal
+group. The @kbd{G n} command in the group buffer (@pxref{Foreign
+Groups}) will do this in an easy-to-use fashion.
+
+@code{nnweb} groups don't really lend themselves to being solid
+groups---they have a very fleeting idea of article numbers. In fact,
+each time you enter an @code{nnweb} group (not even changing the search
+pattern), you are likely to get the articles ordered in a different
+manner. Not even using duplicate suppression (@code{Duplicate
+Suppression}) will help, since @code{nnweb} doesn't even know the
+@code{Message-ID} of the articles before reading them using some search
+engines (DejaNews, for instance). The only possible way to keep track
+of which articles you've read is by scoring on the @code{Date}
+header---mark all articles that were posted before the last date you
+read the group as read.
+
+If the search engine changes its output substantially, @code{nnweb}
+won't be able to parse it and will fail. One could hardly fault the Web
+providers if they were to do this---their @emph{raison d'etre} is to
+make money off of advertisements, not to provide services to the
+community. Since @code{nnweb} washes the ads off all the articles, one
+might think that the providers might be somewhat miffed. We'll see.
+
+You must have the @code{url} and @code{w3} package installed to be able
+to use @code{nnweb}.
+
+Virtual server variables:
+
+@table @code
+@item nnweb-type
+@vindex nnweb-type
+What search engine type is being used. The currently supported types
+are @code{dejanews}, @code{altavista} and @code{reference}.
+
+@item nnweb-search
+@vindex nnweb-search
+The search string to feed to the search engine.
+
+@item nnweb-max-hits
+@vindex nnweb-max-hits
+Advisory maximum number of hits per search to display. The default is
+100.
+
+@item nnweb-type-definition
+@vindex nnweb-type-definition
+Type-to-definition alist. This alist says what @code{nnweb} should do
+with the various search engine types. The following elements must be
+present:
+
+@table @code
+@item article
+Function to decode the article and provide something that Gnus
+understands.
+
+@item map
+Function to create an article number to message header and URL alist.
+
+@item search
+Function to send the search string to the search engine.
+
+@item address
+The address the aforementioned function should send the search string
+to.
+
+@item id
+Format string URL to fetch an article by @code{Message-ID}.
+@end table
+
+@end table
+
+
+
+@node Mail-To-News Gateways
+@subsection Mail-To-News Gateways
+@cindex mail-to-news gateways
+@cindex gateways
+
+If your local @code{nntp} server doesn't allow posting, for some reason
+or other, you can post using one of the numerous mail-to-news gateways.
+The @code{nngateway} backend provides the interface.
+
+Note that you can't read anything from this backend---it can only be
+used to post with.
+
+Server variables:
+
+@table @code
+@item nngateway-address
+@vindex nngateway-address
+This is the address of the mail-to-news gateway.
+
+@item nngateway-header-transformation
+@vindex nngateway-header-transformation
+News headers have often have to be transformed in some odd way or other
+for the mail-to-news gateway to accept it. This variable says what
+transformation should be called, and defaults to
+@code{nngateway-simple-header-transformation}. The function is called
+narrowed to the headers to be transformed and with one parameter---the
+gateway address.
+
+This default function just inserts a new @code{To} header based on the
+@code{Newsgroups} header and the gateway address---an article with this
+@code{Newsgroups} header:
+
+@example
+Newsgroups: alt.religion.emacs
+@end example
+
+will get this @code{From} header inserted:
+
+@example
+To: alt-religion-emacs@@GATEWAY
+@end example
+
+@end table
+
+So, to use this, simply say something like:
+
+@lisp
+(setq gnus-post-method '(nngateway "GATEWAY.ADDRESS"))
+@end lisp
+
+