== Why is this an issue? When an assembly uses Windows Forms (classes and interfaces from the ``++System.Windows.Forms++`` namespace) its entry point should be marked with the ``++STAThreadAttribute++`` to indicate that the threading model should be "Single-Threaded Apartment" (STA) which is the only one supported by Windows Forms. This rule raises an issue when the entry point (``++Shared Sub Main++`` method) of an assembly using Windows Forms is not marked as STA. === Noncompliant code example [source,vbnet] ---- Imports System.Windows.Forms Public Class Foo Shared Sub Main() Dim winForm As Form = New Form Application.Run(winForm) End Sub End Class ---- === Compliant solution [source,vbnet] ---- Imports System.Windows.Forms Public Class Foo Shared Sub Main() Dim winForm As Form = New Form Application.Run(winForm) End Sub End Class ---- ifdef::env-github,rspecator-view[] ''' == Implementation Specification (visible only on this page) include::../message.adoc[] endif::env-github,rspecator-view[]