% Specification Terminology % % Intended to be included within its own section. \begindeptgroup{pm} \label{s:specdfn} \sigauth{NL} Portions of this section conform to \rfc{2119}: ``Key words for use in RFCs to Indicate Requirement Levels''. Certain terms from the RFC have been expressly avoided; for example, the terms ``should'' and ``should not'' are not used because this specification's audience has the capability to alter the specification to resolve implementation issues and should exercise that ability. \begin{description} \sigauth{NL} \dt{conforming implementation} An implementation that meets all of the requirements of this specification. \sigauth{NL} \dt{Deprecated} When used within context of this specification: the feature or requirement will be removed in future revisions of this specification. \sigauth{NL} \dt{Exempt} Denotes a condition under which an implementation need not conform to a requirement. \sigauth{NL} \dt{implementation} Software that implements this specification. \sigauth{NL} \dt{May; Optional} Alternatively, the adverb ``optionally''; denotes a requirement whose implementation is not required and may be omitted; such \shall be used only to provide flexibility for implementors to exercise their best judgment or to denote requirements that are not essential to the operation of the implementation. \sigauth{NL} \dt{Removed} A feature or requirement mentioned in an earlier revision of this specification has been removed and will not be superseded. \sigauth{NL} \dt{section} The section containing the mention of this term, as well as any subsections contained within it. \sigauth{NL} \dt{Shall; Must} Denotes a mandatory requirement. If an implementation does not implement such a requirement, then the implementation is not conforming and the results under such a requirement are \undefined. \sigauth{NL} \dt{Shall Not; Must Not} Denotes an absolute prohibition. If an implementation does not honor such a prohibition, then the implementation is not conforming and the results under such a requirement are \undefined. \sigauth{NL} \dt{Superseded} The feature or requirement mentioned in an earlier revision of this specification has been removed and replaced by another. \sigauth{NL} \dt{Undefined} The error condition results in behavior that is not defined by a particular standard; this term \shall be used only to document other standards or specifications---it \shall not be used to introduce undefined behavior into this specification. \sigauth{NL} \dt{Unspecified} The behavior is not determined by this specification or is inconsequential to the implementation's operation. \sigauth{NL} \dt{\S} Section reference \sigauth{NL} \dt{\P} Paragraph reference \sigauth{NL} \dt{$\leftarrow$} Store value into variable; as opposed to `$=$', which denotes a declarative (and consequently immutable) assignment. \sigauth{NL} \dt{$\square$} End of example or proof. \sigauth{NL} \dt{$\blacksquare$} End of formal definition. \sigauth{NL} \dt{$\lceil x\rceil$} The ceiling of $x$ (round up to the nearest integer). \end{description} \enddeptgroup