NAK (Negative Acknowledgement)
A NAK (Negative Acknowledgement) character indicates that a message, block, or frame has been received in errored condition across a communications circuit, and that it must be retransmitted.
Also known as:
NACK
Relevant NENA Documents
Note: To find and download the document, copy the document number (like STA-010) from below and search the NENA Standards and Documents page.
NENA-STA-027, NENA E9-1-1 PSAP Equipment Standards