The tag is present in Lintian version 2.104.328. That is the most recent version we know about.
The given init script declares a dependency on a virtual facility that is not known to be provided by any init.d script in the archive. If the dependency cannot be satisfied upon the package's installation, insserv will refuse the activation of the init.d script.
Please refer to https://wiki.debian.org/LSBInitScripts for details.