BUR #60254 has been approved by @evazion.
create implication openbsd -> bsd
I get that this isn't quite the same situation as Linux and its distributions, as BSD derivatives are seperate operating system projects in the same family. Still, I figure this implication would set a good precedent for any future BSDs which make their way here, as someone searching BSD would probably expect any *BSD art (especially FreeBSD) to be included with that. If he makes that same search now, all he gets is non-specific art featuring the BSD Daemon.
Also, yes, somehow OpenBSD is the only BSD derivative on Danbooru right now, unless you count MacOS (which is built off permissively licensed code from a variety of projects, and whose tag doesn't distinguish between pre and post-OS X anyways) or the PS3/4/5's use of the FreeBSD kernel.