- tag "name": visible name of the parameter (depending on the GUI this parameter uses)
- tag "comment": (optional) description of the parameter (support HTML formatting) (not yet supported by all widgets)
- attribute "name": MLT filter parameter name
+ - attribute "paramprefix": a string to be prepended to the parameter value before passing it to MLT
- attribute "default": initial value, format depends on parameter type
- attribute "type": widget (GUI) to use
- "fixed":