Q&A Markup Language?

Hi Folks,

[I am posting this question for a colleague]

Has anyone created an XML vocabulary for Question and Answer data?

Without thinking deeply about it, I suppose that a Q&A vocabulary could
be something as simple as:

<session>
     <question>...</question>
     <answer>...</answer>
     <answer>...</answer>
     ...
</session>

Perhaps someone has already thought more deeply about this and has
created a Q&A vocabulary?  If so, please let me know.  /Roger