A good point about transpositions. Aren't I right in thinking, though, that some transpositions are implicitly already arbitrated by ECO, and also that some positions themselves have two ECO codes? Granted, that still leaves a multitude of cases such as the ones you mention, but perhaps the impossibility of arbitrating on everything shouldn't prevent more clarity being introduced where it's desirable. This includes, I think, cases like the one I mentioned where the correct site-section/forum is theoretically clear. In replying to nexirae's Owen's Defence post on Andy's forum section, for example, I feel ambivalent: on the one hand I obviously want to reply if I think I can say something helpful, but on the other I'm thinking that Glenn (who has in the past helped me personally with a question on this opening) might want to see these posts but will not get to do so, while the converse might be true of Andy.

Of course this still leaves those cases where a post might be calling for a wide range of openings expertise: for example I'd like to start a thread about the possibilities for Black after 1 e4 g6 2 d4 Bg7 3 c4 c5 (and 3 ...d6 4 Nc3 c5). Is multiple posting the way to go here, I wonder, or would that just make confusion worse confounded?

I was intending to post a question on one of the forums concerning a couple of Modern-Averbakh positions (ECO code A42--4, I believe): 1 e4 g6 2 d4 Bg7 3 c4 d6 4 Nc3 Nc6 and then: (1) 5 d5 Ne5!? 6 f4 Nd7 7 Nf3; (2) 5 Be3 e5 6 d5 Nce7 7 c5!?.  But on which forum should I post it? -- I was and am unsure!

While I was thinking about this, I realised (I can't be the only one) that some opening systems attract posts on more than one forum. For example, you can find posts on Owen's Defence in Glenn's 'Daring Defence' section and Andy's '1 e4 ...' section -- I myself have posted to both of these! Can I suggest that this is, on balance, an undesirable situation and that it would be worth clarifying who covers precisely what and what should be posted where? I can see that there may be a few cases where double coverage/posting might be desirable, but that doesn't obviate the need for basic clarity. I'd suggest publishing a clear list organised by ECO code, and the natural way to do this would be to use the divisions/descriptions already existent in ChessPub.