No proof is necessary. I received my Goodwill Ambassadorship award last year at the Costa Linda. I was given a form to fill out at the Hotel, and they called me a few days later to come to the lobby for pictures along with a few other people. I think the tourist bureau picks one hotel per week and if you happen to be staying at that hotel and you qualify, they present you with the award. The Costa Linda was also nice enough to give us a free dinner to honor our loyalty to the island. I did have the longest streak of consecutive years of all the people that received the award when I received mine. 33 years in a row and still counting. Looking forward to year 34 next week.