All reports of declares-possibly-conflicting-debhelper-compat-versions for the archive. The extended description of this tag is:
The source package declares the debhelper compatibility version both in the debian/compat file and in the debian/rules file. If these ever get out of synchronisation, the package may not build as expected.
Refer to the debhelper(7) manual page for details.
This tag has not been emitted in any package tested by Lintian.