1 /*!\page rfc2119 RFC2119 Keywords 2 3 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL 4 NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and 5 "OPTIONAL" in this document are to be interpreted as described in 6 <a href="http://www.ietf.org/rfc/rfc2119.txt">RFC 2119.</a> 7 8 Specifically, the following definitions are used: 9 10 \section MUST 11 \anchor REQUIRED 12 \anchor SHALL 13 This word, or the terms "REQUIRED" or "SHALL", mean that the 14 definition is an absolute requirement of the specification. 15 16 \section MUSTNOT MUST NOT 17 \anchor SHALLNOT 18 This phrase, or the phrase "SHALL NOT", mean that the 19 definition is an absolute prohibition of the specification. 20 21 \section SHOULD 22 \anchor RECOMMENDED 23 This word, or the adjective "RECOMMENDED", mean that there 24 may exist valid reasons in particular circumstances to ignore a 25 particular item, but the full implications must be understood and 26 carefully weighed before choosing a different course. 27 28 \section SHOULDNOT SHOULD NOT 29 \anchor NOTRECOMMENDED 30 This phrase, or the phrase "NOT RECOMMENDED" mean that 31 there may exist valid reasons in particular circumstances when the 32 particular behavior is acceptable or even useful, but the full 33 implications should be understood and the case carefully weighed 34 before implementing any behavior described with this label. 35 36 \section MAY 37 \anchor OPTIONAL 38 This word, or the adjective "OPTIONAL", mean that an item is 39 truly optional. One vendor may choose to include the item because a 40 particular marketplace requires it or because the vendor feels that 41 it enhances the product while another vendor may omit the same item. 42 An implementation which does not include a particular option \ref MUST be 43 prepared to interoperate with another implementation which does 44 include the option, though perhaps with reduced functionality. In the 45 same vein an implementation which does include a particular option 46 \ref MUST be prepared to interoperate with another implementation which 47 does not include the option (except, of course, for the feature the 48 option provides.) 49 50 51 */ 52
