The fact that it cost you a lot of time buttresses my point.  Any documentation we write is likely to get stale; it is only the downstream that knows when these things change and could maintain such a document.  And the easy answer is as Andrew indicated, which is maintained by downstream.  That said, if the various downstreams are using a unified set of names, then the equation would change.  The fact that you had separate sections for separate distributions argues that that is not (yet?) the case, though.

The build instructions in the devguide are more likely to be kept up to date, which is why I suggested we should cross link to them from the main build documentation.