How can I prevent HTML encoding on a FormView?

I am trying to display a property (land) size in the ItemTemplate of a FormView control, and the size value is a string that is sometimes square metres and sometimes hectares, so I can't hardcode a <sup> tag suffix, but I need to display the unit as m<sup>2</sup> when appropriate. How do I prevent the tags being enco开发者_如何学运维ded?

You could use javascript to add/remove the formatting tags when the form-submit event fires.