The tag is present in Lintian version 2.104.244. That is the most recent version we know about.
The Debian diff or native package contains a file ending in
~ or of the form
.xxx.swp, which is normally either an
Emacs or vim backup file or a backup file created by programs such as
debconf-updatepo. This usually causes no
harm, but it's messy and bloats the size of the Debian diff to no useful