It seems to be against several goals of Creole. There is already a markup similar to this proposal, less verbose, with end tags which can be recognized easily, standard and very popular: XML. Since Creole doesn't use single angle brackets, it would be easy to mix both.
We're soon going to have assigned a meaning to all double punctuation signs, so Creole won't be much more complicated than it is now. I'd suggest to reserve $$ for LaTeX math, __ for underlined, -- for deleted text and ++ and %% for future uses (all optional), and we're done. Both !! and ?? are too frequent in plain text to be safe.
-- YvesPiguet, 2007-Apr-2
As far as I know, XML is a general markup language, not a set of text formatting rules. You surely mean HTML or XHMTL or one of the other text-formatting SGML/XML derivatives :)
I'd say that "--" is also too frequent in text to use it for markup, so while it fits so fine semantically with "deleted" and visually with "strike trough", it is better avoided -- see the discussions in HyphenListMarkupProposal. You can always use things like "[-foo-]" of course, but we are just making a poor reimplementation of HTML and friends this way.
-- Radomir Dopieralski, 2007-Apr-03
XML: yes, anything more or less based on SGML, XML or SML
would be better than underscores, and this should be left outside Creole Core.
Double hyphens: I thought the same quickly after posting, but I didn't want to hide my point with a minor edit.
-- YvesPiguet, 2007-Apr-03
I agree that it looks like a poor reimplementation of HTML. I think what you have in mind, Gregor, is something like the %% markup element in JSPWiki you can use to "extend" the markup by simply defining div tags in the css file and use the tag names in combination with the %% element. The comment boxes in this wiki are an example of this:
%%commentbox This text is displayed in a gray comment box on the right hand side %%(color:red) You can also use css directly to make a text red %% %%
Unfortunately I think this collides with the rule of NotNew. It only makes sense to create a common element if a lot of wikis are using similar functionality. I don't know if other engines have this functionality, but I guess it's quite rare. So first of all we would have to find out how many engines are using it already.
Therefore I reject this proposal, unless you prove that it is quite common.
--ChristophSauer, 2007-Apr-03