+@cindex self contained nnfolder servers
+When the marks file is used (which it is by default), @code{nnfolder}
+servers have the property that you may backup them using @code{tar} or
+similar, and later be able to restore them into Gnus (by adding the
+proper @code{nnfolder} server) and have all your marks be preserved.
+Marks for a group is usually stored in a file named as the mbox file
+with @code{.mrk} concatenated to it (but see
+@code{nnfolder-marks-file-suffix}) within the @code{nnfolder} directory.
+Individual @code{nnfolder} groups are also possible to backup, use
+@kbd{G m} to restore the group (after restoring the backup into the
+@code{nnfolder} directory).
+