DR , something is nudging me to agree on ORD [ Chicago ] operating out of T1 as well as MIA.
Flight numbers on Short Haul are Even going out and Odd home . Longhaul the opposite Odd outbound , Even homebound !
Why ? I've no idea , but been like that since BA formed [ Mar '74 ].
Rereading this post , I see my memory was as bad just 1 yr ago .. Sorry DH for you having to repeat .
rgds condor .