This should be decided first even though it is editorial.

I propose to move the thread-relatedstuff into a separate SRFI 227, which would explicitly depend on SRFI 226.  That way, people who are concerned with high-level threading but not the details of continuation marks and prompts can discuss these questions concurrently with, but separately from, the rest of SRFI 226 (prompts, continuations, marks, parameters, initial continuations, promises, exceptions).  I think this will be important during the SRFI discussion phase as well as later (as distinct from just splitting it off into a library or two).

Another editorial note: a table of contents should be provided: you cannot search for, say, "5.10" in the browser, as it's being supplied by CSS.