The tag is present in Lintian version 2.109.24. That is the most recent version we know about.
This package includes perl modules using obsoleted perl 4-era
libraries. These libraries have been deprecated in perl in 5.14, and
are likely to be removed from the core in perl 5.16. Please either
remove references to these libraries, or add a dependency on
libperl4-corelibs-perl | perl (<< 5.12.3-7) to this package.