- unwritten - based on custom rather than documentation; "an unwritten law"; "rites...so ancient that they well might have had their unwritten origins in Aurignacian times"- J.L.T.C.Spence
Antonyms: written, codified, statute
- oral, unwritten - using speech rather than writing; "an oral tradition"; "an oral agreement"
Antonym: written (indirect, via spoken)
- ad-lib, spontaneous, unwritten - said or done without having been planned or written in advance; "he made a few ad-lib remarks"
Antonyms: scripted, written (indirect, via unscripted)