I am qualified at not very much if I need a certificate, but I am trained in the writing of risk assessments and method statements and coshh, also first aid, fire fighting and lots of other things, also trained in ladder use and wfp, can I prove any of it, no probably not, well maybe I could if I went up the attic and pulled a few course contents apart.
I took on a young lad via our local council and I was interviewed and interrogated by the H&S guy, he was happy with my answers, and allowed me to put the lad on a few courses, including using a ladder.
a H&S bloke from a job I did in a bus station rightly kicked the last contractor of site as he tried to wfp the windows in the day time. he tried to pull me up at 5am, I pointed out the risks of ladders and the lesser risk of tripping with no one around at 5am, he went for the lesser risk
it is common sense on most parts but I suppose a certificate helps protect you in case of a court case