[edh]

I think 38 still has that distinction for the time being :XXXVIII. 88 will replace that (I think) ... LXXXVIII ... And any that beat that will end with 88.

Year-wise, 1988 is the longest Roman Numeral string to date (MCMLXXXVIII) ... that will be beat in 2988 with MMCMLXXXVIII.

[ConservativeStatement]

Thank you. It was a legit question. It will take an extraordinary effort on the merchandise manufacturers to fit the 2988 year onto a cap.