Gold cards original definition is a charge card or credit card issued to people with a high credit rating and giving benefits not available with the standard card but in this case it is a person such as a significant other who is in fact "the one"

When you want someone dead you put their name on the "Gold Card" as shown in Deadpool

Gold Card; meaning the coveted Starbucks Gold Rewards Card. It's what every white girl dreams of achieveing, it's the fuel of creativity, it is the Starbucks Card. (All it is, is just a gold colored card with your name on it for buying 30 drinks at Starbucks).