What do the letters proceding a train number like Q680 or X652 mean anyway. I notice this a common CSX and BNSF thing.
That looks like CSXT but not BNSF, unless BNSF recently changed.
Here is an example of BNSF trains except locals: M BARRIC1 16
M - train type, in this case manifest freight
BAR - Origin, in this case Barstow, CA.
RIC - Destination, in this case Richmond, CA.
1 - Section, in this case the first section
16 - Origin date, in this case the 16th day of the month
Here is an example of BNSF Locals: L NCA (there are some numbers afterwards, however I do not remember how many).
L - Local
NCA - Railroad Division (or whatever BNSF calls it), in this case Northern California
The numbers afterward designate the specific local.
There was a thread on this subject recently.
http://www.trains.com/community/forum/topic.asp?page=1&TOPIC_ID=28416