Yeah, given the robust communities other markup syntaxes benefit from (the most readable being Markdown), I'm surprised to see a roll-your-own here. Why maintain your own reinvented wheel when there are so many really good ones out there (and that also come with good user penetration). As far as hashtags, I don't think it will be interpreted as a header unless it's at the beginning of a line so wouldn't that rule out most cases?
It basically started with news.arc, the HN source, which apes some of the functionality of markdown in Arc. What we have was the result of me adding to that incrementally. forwardslash and I'll will get together and discuss the best way forward to a happier place. 'most cases' is what bites you in the ass with designing a markup. ;)As far as hashtags, I don't think it will be interpreted as a header unless it's at the beginning of a line so wouldn't that rule out most cases?
I don't think any of these light weight markup language are capable of eliminating the known edge cases without compromising their usability. You just have to find the right balance that fits your use case. The reason I lean towards (Multi)Markdown is because of the aforementioned wide adoption (lots of users know it; lots of solid libraries support it). Beyond those things it mostly just comes down to personal preference when selecting a markup language.'most cases' is what bites you in the ass with designing a markup. ;)