Constant KNOWN_SETUP_OPTIONS 

const KNOWN_SETUP_OPTIONS: &[u64];

The Setup Option types this draft defines.

Section 10.3.1 assigns PATH, AUTHORIZATION TOKEN, MAX_AUTH_TOKEN_CACHE_SIZE, AUTHORITY and MOQT_IMPLEMENTATION.

The list exists for one rule and one direction. Section 10.3: “Receivers MUST allow duplicates of unknown Setup Options.” A receiver may therefore refuse a repeat only of a type it can name, and an option outside this list is one an extension defined and this codec has no business closing a session over. Nothing else reads it - unknown options are still decoded and carried, as “Receivers MUST ignore unrecognized Setup Options” requires.