RFC 2938 (rfc2938) - Page 3 of 18
Identifying Composite Media Features
Alternative Format: Original Text Document
RFC 2938 Identifying Composite Media Features September 2000
feature set reference
a brief construct that references some feature set. (See
also: "dereference".)
feature set tag
a name that conforms to the syntax of a feature tag [2] that
is used to denote a feature set rather than a single
feature.
resolution
(See "dereference").
This specification uses syntax notation and conventions described
in RFC 2234, "Augmented BNF for Syntax Specifications: ABNF" [3].
NOTE: Comments like this provide additional nonessential
information about the rationale behind this document. Such
information is not needed for building a conformant
implementation, but may help those who wish to understand the
design in greater depth.
2. Motivation and goals
The range of media feature capabilities of a message handling system
can be quite extensive, and the corresponding feature set expression
[1] can reach a significant size.
A requirement has been identified to allow recurring feature sets to
be identified by a single reference value, which can be combined with
other elements in a feature set expression. It is anticipated that
mechanisms will be provided that allow the recipient of such a
feature set reference to discover the corresponding feature set
expression, but any such mechanism is beyond the scope of this
specification.
Thus, the goals for this proposal are:
o to provide an abbreviated form for referencing an arbitrary
feature set expression.
o the meaning of (i.e., the corresponding feature set expression) a
feature set reference should be independent of any particular
mechanism that may be used to dereference it.
o to be able to verify whether a given feature set expression
corresponds to some feature set reference without having to
perform an explicit dereferencing operation (i.e., without
incurring additional network traffic).
Klyne & Masinter Standards Track