FOLDER container
Defines the parent container for folder pages.
Syntax
FOLDER [identifier] [ ( attribute [,...] ) ]
   folder-page
   [...] 
END
- identifier defines the name of the element, it is optional but recommended.
 - attribute is an attribute for the element.
 - folder-page defines a folder page that contains other form elements.
 
Form attributes
Style attributes
Common: backgroundColor, border, fontFamily, fontSize, fontStyle, fontWeight, textColor, textDecoration. 
Class-specific: collapserPosition, position, lateRendering.
Can hold
Usage
A FOLDER container including PAGE elements defines a folder tab
widget.
Define each folder page with a PAGE container inside the FOLDER
container.
For more details about this item type, see FOLDER item type.