DTD declaration problem for xml file

[basak]

Please adavice the DTD for the below xml file, inside the comment tag, there is html bold tag. I do not know how to declarat the DTD for it.
Please help!!!
Thank you very much.

Example,

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE reviews SYSTEM "reviews.dtd">
<reviews>
<review id="100">
<m-id>1</m-id>
<comment>good <b>MMM</b> ! </comment>
</review>
<review id="100">
<m-id>23</m-id>
<comment>bgghhhh.</comment>
</review>
</reviews>