> Actually I think you make a couple of great points that ought be > mentioned in the draft about implementability. (No chance you'd > have time to craft a paragraph? If not, I'll try pinch text from > above:-) Now that you point it out like that, I'm irritated at > myself for not having included it already! (It rings bells for me.) OK, I think the place for a new paragraph is just before the last paragraph of section 2. How about something along the lines of: A complete and correct specification is not in and of itself a guarantee of high quality implementations. What may seem like minor details can increase implementation difficulty substantially, leading to implementations that are fragile, contain unnecessary restrictions, or do not scale well. Implementation experience has the potential to catch these problems before the specification is finalized and becomes difficult to change. You might also want to change the final paragraph of the section a bit in light of the addition; I'll leave that to you to work out. Hope this helps. Ned