General Nesting Rules 

The following nesting rules are derived from the table overviews above and arranged according to design rationales, such as avoiding too much framing and avoiding redundant headers.

Avoid Redundant Headers

The nesting rules defined for the layout hierarchy strive for avoiding redundant headings. Thus, do not place:

·        Singular group boxes within areas (Web applications only), or tabstrips

·        Singular tables with a table heading within group controls

Avoid Too much Framing (Visual Complexity)

Too many frames and borders make screens visually complex and waste screen space. Thus, do not place:

·        Singular tables with a table header within group controls - use a table heading instead

·        Singular tabstrips within group controls - Web applications: place them in areas instead; use header texts, or the area header as a title for the tabstrip

·        Group controls within group controls - use groups with text headers and separators instead (not forbidden but should be used with care - try to use different types for the nesting)

·        Tabstrips within tabstrips - nesting tabstrips is a perfect way of information hiding

·        Separator lines between containers or container-like elements.