The following HMTL markups are allowed:
<p> <br> <a> <font>
<b> <i> <s> <sub> <sup> <small> <tt> <u>
<h1> <h2> <h3> <h4> <h5> <h6>.
The <font> markup understands the following attributes: face, color, and size.
The size attribute can be:
Rich text is mainly used by TextLabel, GridView cells, and the Draw.RichText method.