The tag is present in Lintian version 2.104.244. That is the most recent version we know about.
This package is architecture all and hence requires a Multi-Arch foreign value.
An Architecture: all package to satisfy the dependencies of a foreign-architecture package, it must be marked Multi-Arch: foreign or Multi-Arch: allowed.
Refer to https://wiki.ubuntu.com/MultiarchSpec#Dependencies_involving_Architecture:_all_packages for details.