And not just Citi. Every MC in my wallet has one or the other, except for a Diners Club USA charge card (from Harris/BMO), which has neither.

At Citi, are all the lowest MC cards "World", or is there something lower than World (for people who "don't qualify for" a World)? Over at Visa, below Visa Signature there's a Visa Platinum Plus (BofA Alaska card gives 25k miles bonus for the former but only 5k bonus if you get the latter), and that makes me wonder if there's a Visa Platinum (Minus) below the Visa Platinum Plus? And, if so, is there something equivalent below MC World?