In reply to bigrob:
Usually discussed on training /assessment. ABC guidelines are ratio of no more than 1:9, most walls stick to 1:8, going down to 1:6 for younger children, 1:4 if teaching lead climbing.
Don't know of any wall that would allow anyone under 14 to register as an independent climber. Moot point anyway, as if there as part of a supervised session they would count towards your ratio anyway.
Is a bit of a gray area, but ABC suggest that an instructor should not be supervising more than two ropes at once. Have read an H&S Exec document on peer belaying that suggests it should only be one.
Like many things, these are not legally binding. (Though ABC can revoke your membership if guidelines are breached) The difficulty would be if there was an incident and you had to explain why you were not working to industry standards.
Insurance company, local authority, board of directors, parents, press, social media, that wee woman along the street that always walks her dog....... may also have something to say about it.
Post edited at 00:39