Types are declared in namespaces in order to prevent name collisions and as a way to organize them into the object hierarchy. Types that are defined outside any named namespace are in a global namespace that cannot be referenced in code.

Noncompliant Code Example

Public Class Foo
End Class

Public Structure Bar
End Structure

Compliant Solution

Namespace SomeSpace
    Public Class Foo
    End Class

    Public Structure Bar
    End Structure
End Namespace