A while ago, I saw a job ad in the paper looking for a Programmer with Perl and MySQL experience. A couple of weeks later, the same ad appeared but this time round, the requirements say: Degree in Computer Science or Mathematics.
I would imagine this has almost nothing to do with a CS or Mathematics degree being necessary for the job in question. Instead it has everything to do with filtering out the incompetents in the big pile of CVs that the first job advert produced.
What they really need is somebody better at writing job adverts.