[zelphirkalt]

I think it might be a complicated thing to add cleanly for all possible use-cases in the implementation. I remember, how knots in my head formed, when I thought about implementing nested inline markup in a markdown parser. For example if you have nestings like: A B C b c a (where the upper case letter marks the start and lower case letter the end of a markup)

The main implementation of reStructuredText is a custom parser, which might be a hassle to modify to accomodate all cases of nesting, including duplicate ones like: A B A text b a a.

But perhaps all the difficulty in this stems from making the symbols used for starting an inline markup the same as for ending it. Otherwise it would be trivial to count opening and closing "parentheses".