Thanks for the offer, but I'm having more of a problem with working out what to say than how to say it. I need to demonstrate that I meet a bunch of criteria while not breaching commercial confidentiality on the projects I did. The logical place to ask for help with that would be my former employers but they know nothing of this sort of certification, and can be tremendously paranoid about IP and NDAs and suchlike, and also their HR people are pretty useless (at the moment I'm still trying to get them to give me any sort of records of the professional development activities I did while working for them) so I reckon I'll just have to write something myself and then see if my ex-boss is okay with it. He himself is very likely to be, and will make useful suggestions if not, but that still leaves me having to find a line first to be able to write it.