Unwritten
WordNet
adjective
(1) Said or done without having been planned or written in advance
"He made a few ad-lib remarks"
(2) Using speech rather than writing
"An oral tradition"
"An oral agreement"
(3) 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