unspoken rule

Noun

A rule that is understood to apply but does not exist in written form.

Japanese Meaning

暗黙のルール（書かれていないが、皆が理解し、従っている規範）

There is an unspoken rule in our office that you should never eat at your desk during meetings.

私たちのオフィスでは、会議中に机で食事をしないという暗黙のルールがある。

Sense（1）

A rule that is understood to apply but does not exist in written form.

unspoken rules

（ plural ）