Pin Eight:Manual of Style/RFC 2119

"RFC 2119: Key words for use in RFCs to Indicate Requirement Levels" is a RFC memorandum published by the Internet Engineering Task Force that describes the standard meanings of modal verbs and some other words used in Internet standards documents. Documents that use RFC 2119 indicate that RFC 2119 applies to a given word by writing the word with all capital letters.

The most common key words are
 * MUST or MUST NOT: Something is absolutely required.
 * SHOULD or SHOULD NOT: Something is strongly recommended.
 * MAY: Something is allowable either way.

Not all pages on this wiki need to indicate requirement levels. Pages that are descriptive rather than prescriptive, that is, those that describe what is rather than what ought to be, need not use this convention. But pages that do indicate requirement levels SHOULD use this convention and SHOULD use the template RFC 2119, which produces a notice that floats to the right, lest readers confuse these all-capital words with shouting.