I have more answers...
Take my frame number
The M is the factory.
M is Marvel, F is Fairly and T is Ti sports
7 is the model number. Exclude the Ti bikes and work down the list eg.
1 Team Issue
2 Team Marin
3 Pine Mountain
4 Eldridge grade
5 Bear Valley
7 Palisades Trail
8 Bobcat Trail
4 is the year ending number. That would be 1994.
HA is month and date, but you will need the Enigma machine to decode these. Not really relevant either!
B is the size centre to centre.
A is 14 inches
B is 15.5 inches ( this makes it 17 centre to top)
C is 17 inches
D is 19 inches
E is 20 inches
182 are production numbers that are factory use only, and again require the Enigma machine.
Only recently I've bought a 1994 Team Issue with frame no. F04LA0xxx
F= Fairly factory
4= 1994 (I can confirm that)
LA= Month and date, as above
xxx= Production numbers, as above
Seems a bit odd, when trying to follow the decoding as suggested, althouh some fit.
Moreover, two more numbers are stamped into the bb shell: "40 03" and "BI-0261". Whatever these mean.