Today, things have changed. Now, flip-up (or modular) helmets can be approved in both categories: P (= full-face helmet with protective chin guard) and J (= Jet helmet, without chin guard).
Up to now, the standards classified flip-up helmets only as "P" if the flip-up chin guard met standard or "NP" if it did not pass the tests for the chin area for full-face helmets.
Starting in September, all Nolan (mod. N100E, N102, N103) and X-lite (mod. X-1002) flip-up helmets will be labelled P-J.
Previously approved as "P" and already sold, these models have be subjected to additional lab tests in their Jet configuration (that is, with the chin guard open) without making any changes to them. All of them received approval for the extension, thus the "J" will be added.
In any case, for best protection, Nolan recommends that users always ride the visor and chin guard closed.