+@node NNTP marks
+@subsubsection NNTP marks
+@cindex storing NNTP marks
+
+Gnus stores marks (@pxref{Marking Articles}) for @acronym{NNTP}
+servers in marks files. A marks file records what marks you have set
+in a group and each file is specific to the corresponding server.
+Marks files are stored in @file{~/News/marks}
+(@code{nntp-marks-directory}) under a classic hierarchy resembling
+that of a news server, for example marks for the group
+@samp{gmane.discuss} on the news.gmane.org server will be stored in
+the file @file{~/News/marks/news.gmane.org/gmane/discuss/.marks}.
+
+Marks files are useful because you can copy the @file{~/News/marks}
+directory (using rsync, scp or whatever) to another Gnus installation,
+and it will realize what articles you have read and marked. The data
+in @file{~/News/marks} has priority over the same data in
+@file{~/.newsrc.eld}.
+
+Note that marks files are very much server-specific: Gnus remembers
+the article numbers so if you don't use the same servers on both
+installations things are most likely to break (most @acronym{NNTP}
+servers do not use the same article numbers as any other server).
+However, if you use servers A, B, C on one installation and servers A,
+D, E on the other, you can sync the marks files for A and then you'll
+get synchronization for that server between the two installations.
+
+Using @acronym{NNTP} marks can possibly incur a performance penalty so
+if Gnus feels sluggish, try setting the @code{nntp-marks-is-evil}
+variable to @code{t}. Marks will then be stored in @file{~/.newsrc.eld}.
+
+Related variables:
+
+@table @code
+
+@item nntp-marks-is-evil
+@vindex nntp-marks-is-evil
+If non-@code{nil}, this back end will ignore any marks files. The
+default is @code{nil}.
+
+@item nntp-marks-directory
+@vindex nntp-marks-directory
+The directory where marks for nntp groups will be stored.
+
+@end table
+