1. /enkw/ or /enk/ ENQuire. The mnemonic for ascii character 5.

2. An on-line convention for querying someone's availability. After opening a chat connection to someone apparently in heavy hack mode, one might type "SYN SYN ENQ?" (the SYNs representing notional synchronisation bytes), and expect a return of ack or nak depending on whether or not the person felt interruptible.

Compare ping, finger.

[jargon file]