Decoding something in an ATSF timetable

I have the April, 1994 ATSF timetable. Under “Radio Communications” the following is listed:

RADIO _______________Tone_Call-In
COMMUNICATION_____CH___DS___SC___MC___CQS__EMER

Holiday to N.R. Jct. _20____2_____3_____4_____5______9


(Apologies for the underlinesl. It is the only way I know to insure
everything will line up.)

I understand CH is the AAR radio channel. I suspect that DS is the
Dispatcher tone number and EMER is the emergency tone number.

I haven’t had much luck puzzling out the abbreviations “SC”, “MC”,
and “CQS”. Can anyone help me complete my understanding of this?

Thanks!

SC = Signal desk, Signal Caller
MC = Maintenance Desk
CQS= Centralized Quality System (Car Billing Clerk), Centralized agents office for the division

All had their spaces, PODs, in the Scumburg, er…um Krebs Central, er um SOC/Systems Operations Center in Schaumburg, IL…They are finally wising up and dispersing the DS’s again…IMHO Centrallizing stroked a few egos in the operating department while the railroad failed to be responsive to all but those in the nosebleed section and made everything less efficient.

Thank you!