What does the word manifest mean? example: a CSX SD40 and tow Union Pacific C449’Ws are pulling a manifest east. what does it mean?
Manifest to us is just a train with a lot of different loads in it. My guess is you get it from having a wheel that looks like a shipping maifest for a nightmare! Just basiclly loose car train not every car going to the same place ( or in some cases they are)
BNSF has a M for normal slow old park in a siding manifest and H for high priority manifest ( park in front of M train in siding 
)trains. some are like long distance yard transfers (M GALLIN is galesburg yard to Lincoln yard and runs any cars going to them and points inbetween)
I hope this helps