NAK: /nak/ [from the ASCII mnemonic for 0010101] interj.

:NAK: /nak/ [from the ASCII mnemonic for 0010101] interj.
1. On-line joke answer to {ACK}?: "I'm not here."
2. On-line answer to a request for chat: "I'm not available."
3. Used to politely interrupt someone to tell them you don't
understand their point or that they have suddenly stopped making
sense. See {ACK}, sense 3. "And then, after we recode the
project in COBOL...." "Nak, Nak, Nak! I thought I heard you
say COBOL!"
-- The AI Hackers Dictionary