Madness reigns.....
Allowed airside; cars with full petrol tanks, various vans , fuel tankers etc etc, all with enough space to hide anything bomb size( or indeed a can of coke,butter etc that might have 'fallen' under the seat)
Not allowed; any liquids, butter, soup ,milk etc etc that you may have carried on your person through security and might reasonably want to have for lunch/supper on a 9 hour shift whilst stuck airside
This is to secure the restricted zone, which is partly surrounded by an impenetrable four foot fence.
I could list endless laughably pathetic consequences of the rules at my particular airport but frankly if the ****wits in charge thought they were a good idea in the first place they're not going to listen to anyone who can see how the rules work on a day to day basis.