The tag is present in Lintian version 2.104.244. That is the most recent version we know about.
The Debian diff or native package contains files in an .svn
directory. These are usually artifacts of the revision control system
used by the Debian maintainer and not useful in a diff or native package.
dpkg-source will automatically exclude these if it is passed
-i for native and non-native packages respectively.
Refer to the dpkg-source(1) manual page for details.