The tag is present in Lintian version 2.104.244. That is the most recent version we know about.
The package ships two files with the same name installed both in /lib*/ and /usr/lib*/ (or their subdirectories). This is not useful and is incompatible with the merged /usr directories scheme.
Shared library files, both static and dynamic, must be installed in the correct directories as documented in Policy 8.1.