The tag is present in Lintian version 2.113.26. 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 a1e47cb. For merge requests, please use the latest version in the Lintian check fields/homepage.
The "Homepage:" field in this package's control file does not contain a valid absolute URL. Most probably you forgot to specify the scheme (e.g. http).
This tag is also triggered if the scheme is not known by Lintian.