CPDLC
CPDLC stands for Controller-Pilot Data Link Comm's
Normally pilots check in as: C/s, FL, then they say cpdlc.
The other day some1 calls in as that -spelling the cpdlc:cee-pee-dee-el-cee- as usual, but my guess is that the crew got a bit puzzled when they heard as a reply:
XXX, R-E-S-P-E-C-T, u're identified.
cheers, A.