Hate to Ask - Please help - I'm Stupid

Multi Zone Newbie Here.

I am evaluating a display model Marantz SR9600 and want to set it up for multi zone use if I buy it.
The manual is incredibly vague about purpose and proceedures for these related connections:

IR RECEIVER IN
FLASHER IN
EMITTER OUT
MULTI RC

I would really appreciate if someone could explane the differences and relationships between them an if possible, offer examples of actual products used in these applications.

Thanks very much

Don