I have been thinking more about escape. I have started leaning towards the "Escape character should be core" idea (in conjunction with "Escape character should escape a single character" and "Escape character should be ~"). I think it fits well with any future expansion of Creole. However, my real concern is what to do with preformatted block content and external links containing escape characters which are not rendered in the final output. For me, escaping whole Creole markup sequences is not a broad enough solution and imposes hidden constraints and limits future expansion. It was an excellent idea, but I don't believe it's the right way to go. Either we have all or we have nothing.
In the meantime, the simple escape mechanism proposed here for preformatted blocks, I believe, is both adequate and safe. If we don't end up with an escape character then this is the best alternative, without a doubt. Having said that, I will endeavour to work through my escape thinking over the next few weeks and input into any escape arguments.
MarkWharton 2007-05-10