If you're talking about repeating something like a track warrant, it is something you have to learn and I don't know of it ever being practiced in class. Each railroad seems to have their own specific format that they hold the dispatchers to, and therefor the crews. The GCOR was a good idea, but there are now so many exceptions to it that it becomes frustrating if you happen to work between a couple Class 1s and a shortline.

The bigger problem might be how little time new employees receive training before they are "qualified" and thrown to the wolves. THey really need to spend a minimum of 6 months working as a brakeman (braker/switcher to be politically correct and gender neutral) before being promoted to conductor, during which time hopefully a good conductor can be sure they know what they are doing. I really love it when new employees answer the radio with "Go ahead" - only to be topped by "Go ahead and come back!" I have trained a few conductors both on the GCOR and OJT, and also as an engineer been accused as being hard on conductors.

Of course most dispatchers seem to have to much work assigned and seem to be impatient with a newby trying to repeat an authority.