A lot of schools use the cheap PMR446 radios that are available. They use them to control traffic on-site, control student flow about the buildings, and to announce when students are being let out.
It is all against Safeguarding Guidelines, and this is why:
From my experience, Schools do not know how radios work.
On PMR446 there are “Channels” and “Privacy Codes”.
So you can set your radio to channel 7, Privacy Code 4 (or whatever), and think that nobody else can hear you.
Well, it doesn’t work like that.
Anyone who spent about a fiver on a crap radio can hear what you are discussing.
Everything you say, about every pupil, is being broadcast.