CAPN

Capn is a term with several potential meanings. First, as a contracted form of "Cap'n," Capn commonly appears in nautical slang and popular culture as a shorthand for captain. In writing and captions, the apostrophe form "Cap'n" is standard, while "Capn" sometimes appears in informal digital text when the apostrophe is omitted.

Second, in technology, Capn may be used informally to refer to Cap'n Proto, a data interchange format and RPC system designed for fast, zero-copy access. The official project name is Cap'n Proto; the command-line tool is capnp, and the schema language uses the .capnp extension. In casual discussions, people may shorten the name to Capn.

Third, Capn may appear as a proper noun in fictional settings or as a nickname in various communities. As with many short forms, its use as a name is variable and not standardized.

In summary, Capn most commonly arises as a shorthand for captain in everyday language and as an informal reference to Cap'n Proto in tech conversations, with additional usage as a nickname or fictional or contextual proper name in some cases.