No, these very special cards belong to no occasion in particular and all occasions. You can pretty much send it just to send. Say “hi” to someone without needing a reason or if there just isn’t a card that fits that special reason.
Think of these cards as the unicorn cards of the greeting card industry. They shouldn’t exist, but everyone knows about them and wants to see one. Don’t deny your friends and family the opportunity to hold one of these legendary cards in person. When nothing else fits, these cards are where to go.