The tag is present in Lintian version 2.109.24. That is the most recent version we know about.
The strings "GNU General Public License" or "GPL" appear in the
copyright file for this package, but the copyright file does not
/usr/share/common-licenses as the location of the GPL
on Debian systems.
If the copyright file must mention the GPL for reasons other than stating the license of the package, please add a Lintian override.
Please refer to Debian Policy Manual section 12.5 for details.