Is the Included Propagators section a duplicate of Propagators Distribution?

[MrAlias]

The Included Propagators section specifies that a W3C tracecontext propagator must be included in the API, however the Propagators Distribution also mentions that a W3C tracecontext propagator must be included (though it says it MAY be included directly in the API).

This seems like duplicate specification at best and possibly even conflicting specification.

The duplication of this specification should be resolved by unifying on the location of this information. It seems Propagators Distribution is the more comprehensive body of work so it seems a better fit there.

The requirement or option that the implementation be included in the API needs to be resolved. Easing a requirement is a backwards compatible change as opposed to making an option now a requirement. Therefore, it would seem the best course of action here is to resolve this by specifying it is an OPTION to be distributed as part of the OpenTelemetry API.