Code:
BA Premier/BA Gold/oneworld Emerald.................. (a)
BA Silver/oneworld Sapphire.......................... (c), (e)
non-FQTV/BA Blue/oneworld non-status/oneworld Ruby... (b), (d)
First (F/A/Z)........................................ (a)
Club World/Club Europe
Fully Flex (J/C) & Corporate Deal fares............ (a)
Restricted (D/R/I/U)............................... (b) Note: Cannot book CW upper deck until OLCI.
World Traveller Plus/World Traveller
Fully Flex (W/Y) & Corporate Deal fares............ (e)
Restricted (E/T/P/B/H/K/M/L/V/S/N/Q/G/O/X)......... (b), (d)
Euro Traveller/Domestics
Fully Flex (Y) & Corporate Deal fares.............. (a)
Restricted (B/H/K/M/L/V/S/N/Q/G/O/X)............... (b)
Travelling with Infants.............................. (a)
Travelling with Children............................. (b)
Additional needs (Wheelchair, Blind, Deaf, etc.,).... (a)
I hope this makes it somewhat clearer. I will do my best to answer any further questions that there may be but this should cover everything that's already been asked.