Whitepaper

Accessory Design Guidelines for Apple Devices

56 years ago

The use of the words shall, shall not, required, prohibited, should, should not, recommended, not recommended, may, optional, and deprecated in a statement have the following meanings:

shall, or required means the statement is an absolute requirement.
shall not or prohibited means the statement is an absolute prohibition.
should or recommended means the full implications shall be understood before choosing a different course.
should or not recommended means the full implications shall be understood before choosing this course.
mayor optional means the statement is truly optional, and its presence or absence cannot be assumed.
deprecated means the statement is provided for historical purposes only and is equivalent to ‘shall not’.