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Xcode 5 can now show info from doc comment in Alt-Click bubble and during autocompletion automatically. Unfortunately it doesn't support Markdown. And for inline code the (uglier) @c param is used
It would be nice if appledoc supports additional params, like @c
Notice the difference for block and nil words:
Sorry for late reply. I had already thought of doing someting like this and there is partial support for headerdoc. It's not in priority list though...