To ensure that implementations correctly handle unknown values and do not fail when encountering protocol extensions they do not understand, this document reserves a range of values for the purpose of greasing; see Section 3.3 of [RFC9170].
Grease values follow the pattern 0x7f * N + 0x9D for non-negative
integer values of N (that is, 0x9D, 0xBC, ..., 0x3ffffffffffffffe).
The following registries include GREASE reservations:
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Setup Options (Section 9.4.1)
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Properties (Section 14.4)
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Session Termination Error Codes (Section 14.5.1)
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REQUEST_ERROR Codes (Section 14.5.2)
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PUBLISH_DONE Codes (Section 14.5.3)
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Data Stream Reset Error Codes (Section 14.5.4)
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MOQT Auth Token Type
Implementations MUST handle unknown values from these registries gracefully according to the rules defined in each section.
Setup Options with reserved identifiers have no semantics and can carry arbitrary values. Endpoints MUST ignore unknown Setup Options as specified in Section 9.4.