True, but this is also an emergent behavior of the Meetup UI. It has no (clear) way to say "I'm interested, might attend, can't commit right now, please remind

True, but this is also an emergent behavior of the Meetup UI. It has no (clear) way to say "I'm interested, might attend, can't commit right now, please remind me day-of." So if you want that reminder — if you want it on your calendar — you have to RSVP as if you were really 100% coming. Meetup doesn't (clearly) offer any other option. I've RSVPed myself with this intent plenty of times. I'd use a "maybe, please remind me" button if it existed. Contrast Doodle.com, which offers a "yellow maybe" option intermediate between "green yes" and "red no."