hmmm... (Looks at Non-Membership card) I guess since I'm a registered non-member I can go in...? (hesitantly opens door) I've got it! Either one must be registered as either a member or a non-member to get in, or the sign is meant to be taken as "NON Members," which would imply that NON is some sort of abbreviation for a special type of member. And I have officially overthought the humor of this. Hahaha.