What is the origin of the idiom "as a matter of form" and when to use it?

The idiom "as a matter of form" is used to indicate that something is done as a standard procedure or out of habit rather than due to necessity or specific intention. It implies that a particular action or behavior is carried out in accordance with established rules, conventions, or customary practices. This phrase is often used in formal settings to describe actions taken because they are required by regulations or tradition.