The tag is present in Lintian version 2.104.244. That is the most recent version we know about.
The version of this package contains
rc, but a misleading Debian version mangling occurs in
debian/watch file. You should use the uversionmangle
option instead of dversionmangle so that the prerelease is sorted by
uscan before a possible future final release.
Refer to https://wiki.debian.org/DEHS for details.