We propose nested forms, which has been forbidden until now. Such nested forms enable nested dialogues. With this change, the FORM element optionally starts with a CAPTION element. Nested forms have two states: open and closed. The default state is closed, and in this state, the form caption is used to provide a captioned "button" to open the form. In the open state the form may be rendered as a dialog box. In this state the submit button acts to close the form but does not send the form's content to the server. The form's METHOD, ACTION and ENCTYPE attributes are ignored for nested forms.
In the body of a form element, subforms reside at the same logical level as paragraphs. Subforms without a caption element are depricated since browsers will not be able to display a meaningful rendering of the nested dialogue.