This new property applies to all top-level windows and dialog boxes (but not MDI child windows) and allows you to set the translucency of a form based on a simple percentage amount, “0” being fully opaque and “100” being fully transparent.
Form with TRANSLUCENCY of 20
Form with a TRANSLUCENCY of 50
FORM with a TRANSLUCENCY of 80
Check out the excellent PAINT.NET application for a good example of using this effect where supporting modeless dialog boxes are rendered translucent when not active.
[Edit: 01 Feb 13 – property renamed to TRANSLUCENCY from TRANSPARENCY]
(Disclaimer: This article is based on preliminary information and may be subject to change in the final release version of OpenInsight 10).
Building OpenInsight 10 
Is transluceny === transparency? If so why not that name if not why not?
Ever so slightly easier for me to pronounce.
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