All reports of systemd-service-file-outside-lib for the archive. The extended description of this tag is:
The package ships a systemd service file outside /lib/systemd/system/
Systemd in Debian searches for unit files in /lib/systemd/system/ and /etc/systemd/system. Notably, it does not look in /usr/lib/systemd/system/ for service files.
System administrators should have the possibility to overwrite a service file (or parts of it, in newer systemd versions) by placing a file in /etc/systemd/system, so the canonical location used for service files is /lib/systemd/system/.
This tag has not been emitted in any package tested by Lintian.