Context: defwysiwyg must be used inside a def or defenv tag (after a inherit tag if present).

Purpose: defwysiwyg declares the defined tag to be a WYSIWYG tag. This does not have any influence on the usual heitml processing. So from a language view the tag is ignored.

The heitml system has a special function used to edit files with a standard HTML or WYSIWYG editor. Since these editors usually do not understand heitml tags, heitml escapes heitml markup in a way that it does not disturb editing and so that it is not destroyed by the editor.

defwysiwyg tells heitml not to escape the defined tag, because the editor can handle it correctly.

Normally you should use defwysiwyg for redefined HTML tags.