S_FALSE
The documentation lists this name without a value.
Documented in Win32
Alternate success value, indicating a successful but nonstandard completion (the precise meaning depends on context).
Return Values (Windows Accessibility features)
The method succeeded in part. This happens when the method succeeds, but the requested information is not available. For example, Microsoft Active Accessibility returns S_FALSE if you call IAccessible::accHitTest to retrieve a child object at a given point, and the specified point is not within the object or the object's child.
Alternate success value, indicating a successful but nonstandard completion (the precise meaning depends on context).
Alternate success value, indicating a successful but nonstandard completion (the precise meaning depends on context).