+(defvoo nnml-marks-is-evil nil
+ "If non-nil, Gnus will never generate and use marks file for mail spools.
+Using marks files makes it possible to backup and restore mail groups
+separately from `.newsrc.eld'. If you have, for some reason, set this
+to t, and want to set it to nil again, you should always remove the
+corresponding marks file (usually named `.marks' in the nnml group
+directory, but see `nnml-marks-file-name') for the group. Then the
+marks file will be regenerated properly by Gnus.
+
+This variable is a virtual server slot. See the Gnus manual for details.")
+