Here are the facts about Unix. * The name "UNIX" or "Unix" is trademarked. * AIX, Solaris and HP-UX are certified Unix systems. These are bonafide Unix systems and there indeed are software developers today who work with these Unix systems.[2] * The set of Unix-like systems is a superset of the set of Unix systems. The set of Unix-like systems include systems like Linux, FreeBSD, etc. which the set of certified Unix…
> By decree of The Open Group, the term "UNIX" refers more to a class of operating systems than to a specific implementation of an operating system; those operating systems which meet The Open Group's Single UNIX Specification should be able to bear the UNIX 98 or UNIX 03 trademarks today, after the operating system's vendor pays a substantial certification fee and annual trademark royalties to The Open Group.
But if I were exchanging information with a candidate, what Stanley provides is more than I would expect from a candidate (even from industry; he seems to be a student); that he isn't exactly on the mark should have been fine. If we really wanted exacts, the recruiter had ample opportunity to explain his/her position, but instead, we get nothing. Stanley took the time to both give his view on things, and give a simple layman's answer that conforms to that view when the tech jargon didn't seem to go over well. That he might be technically wrong is incredibly nitpicky, and I am not persuaded that that was the issue the recruiter had.
It still seems like an extremely weird qualification to require, doubly so again for an intern level position: you would still be likely to pass over extremely qualified candidates who just never touched a "UNIX".