Last time I was involved it was just a simple identifier on the boiler that could tie the certificate to the boiler. No "standard" for the format was specified. Cheers Peter On 2013-01-09 15:51, stepney wrote: > It was a requirment in the Blue Book, and I think, the one before that. > (Was it the red book?) > > So, and this from memory, about 2004 or 5 for the Blue Book, and some 7 > or 8 years earlier, if I am right about the "red(?) Mbook. > > Alan > MODEL ENGINEERING DISCUSSION LIST. > > To UNSUBSCRIBE from this list, send a blank email to, > modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line. MODEL ENGINEERING DISCUSSION LIST. To UNSUBSCRIBE from this list, send a blank email to, modeleng-request@xxxxxxxxxxxxx with the word "unsubscribe" in the subject line.