Each option has at least one @dfn{long} (or @dfn{mnemonic}) name starting with two
dashes in a row, e.g., @option{--list}. The long names are more clear than
their corresponding short or old names. It sometimes happens that a
-single long option has many different different names which are
+single long option has many different names which are
synonymous, such as @option{--compare} and @option{--diff}. In addition,
long option names can be given unique abbreviations. For example,
@option{--cre} can be used in place of @option{--create} because there is no
Automatically excludes all directories
containing a cache directory tag. @xref{exclude}.
+@opsummary{exclude-tag}
+@item --exclude-tag=@var{file}
+
+Exclude all directories, containing file named @var{file}. @xref{exclude}.
+
@opsummary{file}
@item --file=@var{archive}
@itemx -f @var{archive}
use to hold regenerable, non-precious data, so that such data can be
more easily excluded from backups.
+@findex exclude-tag
+Another option, @option{--exclude-tag}, provides a generalization of
+this concept. It takes a single argument, a file name to look for.
+Any directory that contains this file will be excluded from the dump.
+
+@table @option
+@opindex exclude-tag
+@item --exclude-tag=@var{file}
+Causes @command{tar} to ignore directories containing @var{file}.
+Multiple @option{--exclude-tag} options can be given.
+@end table
+
+For example:
+
+@smallexample
+$ @kbd{find dir}
+dir
+dir/blues
+dir/jazz
+dir/folk
+dir/folk/tagfile
+$ @kbd{tar -cf archive.tar --exclude-tag=tagfile -v}
+dir/
+dir/blues
+dir/jazz
+./tar: dir/folk/: contains a cache directory tag tagfile; not dumped
+$ @kbd{tar -tf archive.tar}
+dir/
+dir/blues
+dir/jazz
+@end smallexample
+
@menu
* problems with exclude::
@end menu