Keywords

Definition

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119.

• MUST This word, or the terms REQUIRED or SHALL, mean that the definition is an absolute requirement of the specification.
• MUST NOT This phrase, or the phrase SHALL NOT, mean that the definition is an absolute prohibition of the specification.
• SHOULD This word, or the adjective RECOMMENDED, mean that there may exist valid reasons in particular circumstances to ignore a particular item, but the full implications must be understood and carefully weighed before choosing a different course.
• SHOULD NOT This phrase, or the phrase NOT RECOMMENDED mean that there may exist valid reasons in particular circumstances when the particular behavior is acceptable or even useful, but the full implications should be understood and the case carefully weighed before implementing any behavior described with this label.

Usage

• You MUST format all keywords in uppercase and bold.
• You SHOULD use the four major keywords ("MUST", "MUST NOT", "SHOULD", "SHOULD NOT") only. This is to make a search easier and the rules easier to read.
• You MUST NOT use the short form of the negated keywords
  • "SHOULDN'T" => "SHOULD NOT".