Hello Merritt,
This system is a Nitsuko Portrait 824. It is capable of having CID and SLT's, but there was no digital cordless made for this system. The CID requires a CID/SMDR daughter board and a CID adapter that goes before the CO lines. The NEC/Nitsuko item numbers are:
CID/SMDR daughter board - 82421
CID Adapter - 82425
I can't remember but I don't think that you can send CID info to SLT's but don't hold me to that. One of the cool things about this system is that you can have an SLT on a digital port, like an Avaya Partner system. Also on the CID you have to change something in system programming for the KSU to look for CID. Sorry for the long post but I don't know how familar you are with NEC/Nitsuko. Hope this helps.

Thanks,
Daniel

HAPPY NEW YEAR