Undocumentated
Undocumentated is an English adjective that refers to something lacking documentation or official paperwork. It is a rare and nonstandard form in most varieties of English; the preferred term in formal writing is undocumented, or not documented when referring to objects or processes.
Etymology and usage: The word appears to be formed from the noun document with the negative prefix
Contexts and examples: In software development, a function or API described as undocumentated would imply there
See also: undocumented, documentation, metadata, data provenance, provenance of information.