However, without a clear view of where extensibility may occur, extension may break any content formatted to older creole versions.

For example, if a new creole uses the tilde as escape character, or assigns special meaning to leading hyphens (as discussed in the [[List Markup Alternatives]]), then older content will break that contains tilde or leading hyphens without any markup intentions.

I therefore believe that at least for the case of text-based markup, we need an extensibility container, compare [[Generic Extension Element Proposal]].

-- Gregor Hagedorn - 2007-03-09

The pre-1.0 Creole versions are not required to be backward-compatible. We are basically trying out different things, this is beta (or even alpha). Early adopters must consider converting their wikis when the final specification is released.

Once we have the basic markup sorted out, Creole is supposed to be stable -- that is, only very minor chnages or clarifications will occur, possible rewording of the spec, etc.

That's why we are so bitchy -- whatever is decided now will stay.

-- [[Radomir Dopieralski]], 2007-Mar-10

I agree about versions < 1.0. However, do you agree that the problem of wiki markup always using things also occurring in normal text (even if rarely) makes the main [Extensible By Omission] somewhat inappropriate? I believe it does not work for Wiki markup because you cannot truly extended Creole by adding a new markup (e.g. suddenly giving a + at start of line a markup semantics in Creole 2.0).

-- Gregor Hagedorn - 2007-03-14

Wikis have the advantage that even if the rendering of the page degrades for whatever reason (version change, copy-pasting text from other source, adding additional modules, etc.) the users always have access to the source to see what the author meant -- and the first users who notices the fault can even correct it! The rules prohibiting [[InvisibleMarkup]] and requiring [[NonDestructiveMarkup]] aid here a lot.

Remember that we are not dealing with a rigid automated system that has to give the right results 100% of the time, but with a wiki that is by definition fuzzy and fault-tolerant. This doesn't mean we should take this lightly, but I thin that [[ExtensibleByOmission]] is worth the occasional error.

-- [[Radomir Dopieralski]], 2007-Mar-14