The tag is present in Lintian version 2.114.55. That is the most recent version we know about.
We use semantic versions.
The patch number is a commit step indicator relative to the
release tag in our Git
You can find the detection logic for this version at commit 8053610. For merge requests, please use the latest version in the Lintian check debian/debconf.
Packages using debconf should call
db_purge or its equivalent
in their postrm. If the package uses debhelper, dh_installdebconf(1) should
take care of this.