Custom style tags for reports

[j.t.casperson]

According to documentation, in Jasper you can markup with html, styled, or rtf. The supported tags are <b>, <u>, <i>, <font>, <sup>, <sub>, <li>, and <br> 

I need a way to define my own tags (such as <h1>). I imagine there has to be a way to do this, but so far I haven't been able to find any documentation or answers. Thoughts?

EDIT: Thought I should put more information down as to what I'm trying to do. I understand and use jasper stylesheets with the <style> tag, but what I'm trying to do is something like this: <textElement markup="html"/><textFieldExpression><![CDATA[$F{test_field}+" "]]></textFieldExpression> where $F{test_field}'s vaule might be "<h1>Header</h1>" or "<em>italic text</em>". Anyone know if or how this can be accomplished? In this case regular styles just won't cut it because the field is pulling from wysiwyg like editor that has styling available in it and I'd like to keep those styles in my Jasper report.