I checked a bunch of domestic routes on expertflyer for flights starting 9/30/05. For flights within the 48 contiguous states "A" ceases to be a published fare (it still shows under "available classes" on the flight display, but if you do a fare query there are NO published fares with a booking class of A). Booking class "P" is now generally associated with fare basis codes starting with "YUP..." and the terms/restrictions of these P fares are similar to or identical to A/YUP fares published for prior to 9/30/05. If you book a flight on AA.com for restricted first class where inventory is available it will show a "P" booking code with the YUP fare basis. Transcons are using the same concept, i.e., full first class is now F class, discounted/restricted first is P (with J being full biz and I and D being various discount biz buckets)...on transcon flights the P fares are all lower than the F fares from 9/30.

Hawaii and Anchorage are not consistent with the above. Both still have F class as purchased full first and A code is associated with the purchased YUP... fare basis. If they are trying to rationalize the system it doesn't make sense why they would have these exceptions unless they just haven't swapped these markets over yet.

If there is any rhyme or reason to this change those RTW tickets will book into published/purchaseable fare categories and will therefore start booking into P on 9/30.

Pat: it almost certainly doesn't mean anything for your purposes, you should be able to find discounted first class seats as usual on those flights. This is an esoteric issue of how AA treats award vs. discounted purchased tickets, and the internal nomenclature they use to distinguish different types of premium fares.