unwritten
🇺🇸
/ˌʌnˈrɪtn/
🇬🇧
/ˌʌnˈrɪtn/
Known and followed by people, but not officially made into a rule or law.
There's an unwritten rule in our office that you should never eat someone else's lunch from the fridge.
Not yet put into words or recorded in writing.
She had a great idea for a story, but it was still unwritten.