The tag is present in Lintian version 2.109.22. That is the most recent version we know about.
This link goes up, and then back down into the same subdirectory. Making it shorter will improve its chances of finding the right file if the user's system has lots of symlinked directories.
If you use debhelper, running dh_link after creating the package structure will fix this problem for you.
Please refer to Debian Policy Manual section 10.5 for details.