The tag is present in Lintian version 2.109.21. That is the most recent version we know about.
This binary package appears to be empty, and its description does not say that it's a metapackage or a transitional package. This is often due to problems with updating debhelper *.install files during package renames or similar problems where installation rules don't put files in the correct place.
If the package is deliberately empty, please mention in the package long description one of the phrases "metapackage", "dummy", "dependency package", or "empty package".
Previously, Lintian also accepted the use of "virtual package". This was removed to avoid overloading the term. If you have been relying on the phrase "virtual package" to avoid this warning, please replace it with one of the others.