Unfortunately, the info document describing tar is licensed under the GFDL with
invariant cover texts, which violates the Debian Free Software Guidelines.  As
a result, the info documentation for tar has been completely removed from the
Debian package.  Instead, we deliver a tar man page that was created from
scratch for the Debian project.

If you want to read the complete documentation for GNU tar, please either
install the 'tar-doc' package from Debian's non-free repository, or refer to
the online version at <http://www.gnu.org/software/tar/manual/index.html>.