The forms on the page allow you to re-register a second-hand boat, replace a missing or lost certificate, order a sail number for a new boat and join or renew membership of the National 12 Owners' Association.
National Twelve Class Rules state that change of ownership invalidates the certificate, and any new owner needs to register the boat in their name.
The Registration Certificate/Measurement Certificate issued for each National Twelve will show the current registered owners name and address, and also shows the current sail plan dimensions and hull/spar weights etc.