The package seems to declare several relations to a libpng version. This is not only sloppy but in the case of libraries, it may well break the runtime execution of programs.
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 ea05801. For merge requests, please use the latest version in the Lintian check fields/package-relations.