ACK

ACK
 /ak/, interj.

   1. [common; from the ASCII mnemonic for 0000110] Acknowledge. Used to
   register one's presence (compare mainstream Yo!). An appropriate
   response to {ping} or {ENQ}.

   2. [from the comic strip Bloom County] An exclamation of surprised
   disgust, esp. in "Ack pffft!" Semi-humorous. Generally this sense is
   not spelled in caps (ACK) and is distinguished by a following
   exclamation point.

   3. Used to politely interrupt someone to tell them you understand
   their point (see {NAK}). Thus, for example, you might cut off an
   overly long explanation with "Ack. Ack. Ack. I get it now".

   4. An affirmative. "Think we ought to ditch that damn NT server for a
   Linux box?" "ACK!"

   There is also a usage "ACK?" (from sense 1) meaning "Are you there?",
   often used in email when earlier mail has produced no reply, or during
   a lull in {talk mode} to see if the person has gone away (the standard
   humorous response is of course {NAK}, i.e., "I'm not here").
    

ACK

   1. <character> /ak/ The {mnemonic} for the ACKnowledge
   character, {ASCII} code 6.

   2. <communications> A message transmitted to indicate that
   some data has been received correctly.  Typically, if the
   sender does not receive the ACK message after some
   predetermined time, or receives a {NAK}, the original data
   will be sent again.

   [{Jargon File}]

   (1997-01-07)