the "rules" as you call them are the Manufacturers Instructions (MI), relevant BS docs and probably the water regs, what you need to do is ask someone if you can have a quick look at their boiler and at the very least note the name & model of the boiler or try to get a pic of the pipes under the boiler, post the info here and let us have something to work with for supplying you some ammo for the management agent
The discharge of condensate is actually dealt with under the Building Regulations!
Officially at least, condensate discharge is strictly controlled. It cannot just be dripped onto paths and walkways.
Quite apart from the discharge, it should not be causing any inconvenience or nuisence.
But quite a few PRV discharges are into a gutter beside the path so dont really cause any problem to anyone.
Whilst I have advised you on the factual situation, I am a little concerned that you may be taking an unatural interest in these matters. Why are you so concerned about a few drips which anyone else just walks past?