Thank you to everyone that replied. I believe I do have it figured out now.
Mike, I hear what you're saying regarding the 0,0 tone. My goal was to keep the radio from transmitting altogether. I didn't test it, but I believe your suggestion would have transmitted a silent tone which isn't what I was trying to accomplish.
Steve, I commented out the 'idrecording=' configuration option under my node stanza, and that has effectively disabled the ID. I didn't have to touch anything in the [telemetry] stanza.
So, right now my node is set to duplex=1, there is no ID, and I only hear a courtesy tone when a networked user unkeys.
Here are the pertinent configuration options I set under my node stanza to accomplish this:
duplex=1
;idrecording=|iKC9ONA/L
; Telemetry & Courtesy Tone Options
telemetry=telemetry
;unlinkedct=ct2 ; Sent when not connected to another node
;remotect=ct3 ; Sent when remote base connected
linkunkeyct=ct8 ; sent when a network user unkeys
nolocallinkct=1
eannmode=2
echolinkdefault=0
echolinkdynamic=0
nounkeyct=1
holdofftelem=1
telemdefault=0
telemdynamic=0
guilinkdefault=0
guilinkdynamic=0
phonelinkdefault=0
phonelinkdynamic=0
Thanks!