-tapes), it is a good idea to use the @value{op-verify} option, to make
-sure your files really made it onto the dump properly. This will
-also detect cases where the file was modified while (or just after)
-it was being archived. Not all media (notably cartridge tapes) are
-capable of being verified, unfortunately.
-
-@value{op-listed-incremental} take a file name argument always. If the
-file doesn't exist, run a level zero dump, creating the file. If the
-file exists, uses that file to see what has changed.
-
-@value{op-incremental} @FIXME{look it up}
-
-@value{op-incremental} handle old @acronym{GNU}-format incremental backup.
-
-This option should only be used when creating an incremental backup of
-a filesystem. When the @value{op-incremental} option is used, @command{tar}
-writes, at the beginning of the archive, an entry for each of the
-directories that will be operated on. The entry for a directory
-includes a list of all the files in the directory at the time the
-dump was done, and a flag for each file indicating whether the file
-is going to be put in the archive. This information is used when
-doing a complete incremental restore.
-
-Note that this option causes @command{tar} to create a non-standard
-archive that may not be readable by non-@acronym{GNU} versions of the
-@command{tar} program.
-
-The @value{op-incremental} option means the archive is an incremental
-backup. Its meaning depends on the command that it modifies.
-
-If the @value{op-incremental} option is used with @value{op-list},
-@command{tar} will list, for each directory in the archive, the list
-of files in that directory at the time the archive was created. This
-information is put out in a format that is not easy for humans to
-read, but which is unambiguous for a program: each file name is
-preceded by either a @samp{Y} if the file is present in the archive,
-an @samp{N} if the file is not included in the archive, or a @samp{D}
-if the file is a directory (and is included in the archive). Each
-file name is terminated by a null character. The last file is
-followed by an additional null and a newline to indicate the end of
-the data.
-
-If the @value{op-incremental} option is used with @value{op-extract}, then
-when the entry for a directory is found, all files that currently
-exist in that directory but are not listed in the archive @emph{are
-deleted from the directory}.
-
-This behavior is convenient when you are restoring a damaged file
-system from a succession of incremental backups: it restores the
-entire state of the file system to that which obtained when the backup
-was made. If you don't use @value{op-incremental}, the file system will
-probably fill up with files that shouldn't exist any more.
-
-@value{op-listed-incremental} handle new @acronym{GNU}-format
-incremental backup. This option handles new @acronym{GNU}-format
-incremental backup. It has much the same effect as
-@value{op-incremental}, but also the time when the dump is done and
-the list of directories dumped is written to the given
-@var{file}. When restoring, only files newer than the saved time are
-restored, and the directory list is used to speed up operations.
-
-@value{op-listed-incremental} acts like @value{op-incremental}, but when
-used in conjunction with @value{op-create} will also cause @command{tar} to
-use the file @var{file}, which contains information about the state
-of the filesystem at the time of the last backup, to decide which
-files to include in the archive being created. That file will then
-be updated by @command{tar}. If the file @var{file} does not exist when
-this option is specified, @command{tar} will create it, and include all
-appropriate files in the archive.
-
-The file, which is archive independent, contains the date it was last
-modified and a list of devices, inode numbers and directory names.
-@command{tar} will archive files with newer mod dates or inode change
-times, and directories with an unchanged inode number and device but
-a changed directory name. The file is updated after the files to
-be archived are determined, but before the new archive is actually
-created.
-
-@node Inc Dumps