unwritten law

An accepted although informal rule of behavior, as in It's an unwritten law that you lock the gate when you leave the swimming pool. [Mid-1400s]

Name	Pronounced	Usage
Haruki	hah-ṙoo-kee	Japanese
Bodil	-	Swedish, Norwegian, Danish
Jarkko	YAHRK-ko	Finnish
Airi	ah-ee-ṙee	Japanese
Berthold	BERT-hawlt	German (Archaic)
Binay	-	Bengali