http://www.flyertalk.com/forum/briti...-type-m9a.html
The aircraft type changes from A320 (or A319, A321, 737, 747, 767, 777, etc) to an specific designator around 72 hours before the flight.
3-3 in the first row of economy would indicate space saver seating.
Last edited by nux; Jun 10, 2013 at 8:55 am
Reason: Replaced ex-BMI with Space Saver