ENQ

( /enkw/, /enk/)

   [from  the  ASCII mnemonic ENQuire for 0000101] An on-line convention
   for  querying  someone's  availability.  After  opening a {talk mode}
   connection  to  someone apparently in heavy hack mode, one might type
   SYN  SYN ENQ? (the SYNs representing notional synchronization bytes),
   and expect a return of {ACK} or {NAK} depending on whether or not the
   person felt interruptible. Compare {ping}, {finger}, and the usage of
   FOO? listed under {talk mode}.

[glossary]
[Reference(s) to this entry by made by: {ACK}{ping}]