For required form controls, indicate the required status in the control's "+'"label" or "legend". If not indicated by text (like "(required)"), then make sure the meaning of the indicator is explained before it is used. NOTE: Abbreviating "required" to "req." may be confusing. Visit http://www.w3.org/TR/WCAG20-TECHS/H90 for more information.
Provide a semantic grouping for related form controls using the "fieldset" and "legend" elements. This is most important for related radio buttons and checkboxes. If desired, CSS can be used to change the visual effect of using the elements. Visit http://www.w3.org/TR/WCAG20-TECHS/H71 for more information.