I know this is an old thread, but i have the same issue and instead of doing a new thread i thought i could ask you guys here.
I'm going this weekend to do my CAA class 1 medical renewal in Dubai with Dr. Akel, but i've been told that i should present my old medical certificate, and a Reference number that i get from GCAA website etc...
Can you tell me what do they mean by that reference number?! because i registered on gcaa.gov.ae and i didn't receive any reference number.