Conformance requirements are expressed with a combination of + descriptive assertions and RFC 2119 terminology. The key words “MUST”, + “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, + “RECOMMENDED”, “MAY”, and “OPTIONAL” in the normative parts of this + document are to be interpreted as described in RFC 2119. + However, for readability, these words do not appear in all uppercase + letters in this specification. + +
All of the text of this specification is normative except sections + explicitly marked as non-normative, examples, and notes. + \[RFC2119]
+ +Examples in this specification are introduced with the words “for example”
+ or are set apart from the normative text with class="example",
+ like this:
+
+
This is an example of an informative example.
+Informative notes begin with the word “Note” and are set apart from the
+ normative text with class="note", like this:
+
+
Note, this is an informative note.
+ +Requirements phrased in the imperative as part of algorithms (such as + "strip any leading space characters" or "return false and abort these + steps") are to be interpreted with the meaning of the key word ("must", + "should", "may", etc) used in introducing the algorithm.
+ +Conformance requirements phrased as algorithms or specific steps can be + implemented in any manner, so long as the end result is equivalent. In + particular, the algorithms defined in this specification are intended to + be easy to understand and are not intended to be performant. Implementers + are encouraged to optimize.
+