Permanent Part-Time work while studying

Hello,
I am currently studying in the UK and was wondering if I am allowed to take a permanent part-time job whilst studying on my Tier 4 visa. On the UKBA website, it says

The work you do must not fill a full-time permanent vacancy (other than on a recognised Foundation Programme), and you must not be self-employed, employed as a doctor in training (except on a recognised Foundation Programme) or as a professional sportsperson, coach or entertainer.

(source: http://www.ukba.homeoffice.gov.uk/study ... onditions/#)

But it doesn't say anything about part-time permanent vacancies, so I'm confused. I intend to get a PSW visa after completing my studies so would be able to stay in the post for quite some time (if I get the job!) but don't want to break any rules. And I would, of course, explain my situation and not mislead anyone into thinking I would work for them longer than I intend to have a valid visa here. Anyone know anything about this? Thanks so much for your help.