1 Scope
This Recommendation | International Standard specifies a set of Basic Octet Encoding
Rules (BASIC-OER) that may be used to derive a transfer syntax for values of the types
defined in Rec. ITU-T X.680 | ISO/IEC 8824‑1, Rec. ITU-T X.681 | ISO/IEC 8824‑2, Rec. ITU-T X.682 | ISO/IEC 8824‑3, Rec. ITU-T X.683 | ISO/IEC 8824‑4. This
Recommendation | International Standard also specifies a set of Canonical Octet Encoding
Rules (CANONICAL-OER) which provides constraints on the Basic Octet Encoding Rules
and produces a unique encoding for any given ASN.1 value. It is implicit in the specification
of these encoding rules that they are also to be used for decoding.
The encoding rules specified in this Recommendation | International Standard:
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– are used at the time of communication;
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– are intended for use in circumstances where encoding/decoding speed is the major concern in the choice of encoding rules;
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– allow the extension of an abstract syntax by addition of extra values for all forms of extensibility described in Rec. ITU-T X.680 | ISO/IEC 8824‑1.