F4 A1 J4 D2 I1 means
at least 4 seat available for full fare F (maybe 7,8 or 12)
only 1 of these will be sold for the disc A class
therfore, F4A4 means >4 in both A&F, but the plane could have a max of 4 or 5 or 12 seats. (Not necessarily 8, 8 is, in fact, a meaningless number in this case)


similarly for J/D/I

if an A is sold, it becomes F4A0, or F3A0, depending on what max the original F was. the airline revenue management will examine the situation again, and may want to release more seats to A subclass.

F4A4 means at least 4 F seats avaialble, within this inventory at least 4 will be sold at subclass A. it does NOT mean there are 8 seats. an aircraft with max 4 seat can (in theory) be listed at F4A4


in the same token
Y9B9...S9V9
simply mean there are at least 9 (NOT 99) seats available for sale in all subclasses. if a V is sold. it will become
Y9b9......V8, or Y9B9....V9 still,
or
Y8B8....V8 in theory, depends on what the original Y/B/S max were.


hope this is clear
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regarding why the max for A is 4, and that for JDIYB is 9. i think it has to do with the history and getting s common standard, and the fact that some planes in the past only had 4 F seats, or whatever reason. that the CRS agreed to a common standard (for different aircrafts)

the other reason could be that the airline does not want to publish the real max (?), so that they have the control on the last few seats

note for sabre/aa the max for J/Y is 7, instead of 9. my take is that 7 is exactly the max for 3 bits (0/1/...7). it is probably designed back when computer memory were so expensive



[This message has been edited by pegasus8228 (edited 01-22-2003).]