Petty, I know

[Neapolitan Ice Cream]

I have a few certificates that simply state that I am a member of a professional Guild. THey're not worth much, BUT, they do LOOK the part and are deadly rare - you can get modern certificates but they are more colourful cheesy ones. I got the last of the run, and even then they didn't hand out the certificates readily. You could say I prize them as many people prize a rare comic book!