I was recently corrected, and according to the HTML4 DTD, it is legitimate to use a fieldset outside of a form: http://www.w3.org/TR/html401/sgml/dtd.html#block
Previously I had not known this, and wonder if anyone can think of a legitimate use case for doing so. I feel like using one to decorate would be frowned upon by most designers. So is there a legitimate use case, or can you link to a site where this has been found appropriate and used as such?
I used a field set to decorate sections when printing documents. For example an invoice might have a Bill To and a Ship To, and drawing the frame around them with the legend text embeded in the frame can look really slick.