And OF = Old First.

OF is largely still on Mid-J 744s.

Mid-J 744s are still prevalent on routes such as LAX and SFO.

Mid-J is where WTP gets to disembark before F and J and has the added bonus of Club Kitchen

This could be confusing you...

NF is the most recent First refurbishment. Not all aircraft have been refitted but certain routes like JFK are virtually guaranteed to have NF. Some routes are more of a lottery. The dice are getting more loaded in favour of NF.

Thales IFE is the latest most up to date IFE system with screens that you can actually watch a movie on. Not all NF aircraft have the Thales IFE. 744 aircraft will not have Thales (only available on some 777s). Only aircraft guaranteed to have both NF and Thales is the 777-300 (773).