2 Language Notes

  • Article

In this specification, the words that are used to define the significance of each particular requirement are capitalized. These words are used in accordance with their definitions in RFC 2119 [RFC 2119] and their meaning is reproduced here for convenience:

  • MUST. This word, or the adjective “REQUIRED,” means that the item is an absolute requirement of the specification.

  • SHOULD. This word, or the adjective “RECOMMENDED,” means that there may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood and the case carefully weighed before choosing a different course.

  • MAY. This word, or the adjective “OPTIONAL,” means that this item is truly optional. For example, one implementation may choose to include the item because a particular marketplace or scenario requires it or because it enhances the product. Another implementation may omit the same item.