The changelog file has an instruction left by dh_make, which has not been removed. Example:
- Initial release (Closes: #nnnn) <nnnn is the bug number of your ITP>
The "<... is the bug number ...>" part has not been removed from the changelog.
The tag is present in Lintian version
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 3410a22. For merge requests, please use the latest version in the Lintian check debian/changelog.