ACK

Writing & Everyday abbreviation · Email and Office

ACK
Stands forAcknowledged
CategoriesWriting & Everyday

ACK stands for Acknowledged, an email and office abbreviation.

Confirms that a message, request or instruction has been received and understood, without necessarily agreeing to it. It is used in operations teams, military communications and engineering chat.

Example: ACK, I'll look into the server alert after the 10 a.m. standup.

Usage notes

The term comes from data communications, where an ACK signal confirms receipt of data and a NAK reports a problem, as in TCP's acknowledgment mechanism. In incident-response tools, "acking" an alert means taking ownership of it. In comics and chat, "ack" is also a cartoonish exclamation of dismay.

More email and office abbreviations

  • 1:1 – One-on-one (meeting)
  • AOB – Any other business
  • ASAP – As soon as possible
  • BCC – Blind carbon copy
  • BLUF – Bottom line up front
  • BR – Best regards
  • CC – Carbon copy
  • COB – Close of business
  • COP – Close of play
  • DL – Distribution list
  • Encl. – Enclosure
  • EOB – End of business

See all 60 email and office abbreviations →