GLCore.cs: EnableClientState()

In Source\Compatibility\Graphics\GL\GLCore.cs functions:

[System.Security.SuppressUnmanagedCodeSecurity()]
[System.Runtime.InteropServices.DllImport(GL.Library, EntryPoint = "glEnableClientState", ExactSpelling = true)]
internal extern static void EnableClientState(OpenTK.Graphics.EnableCap array);

[System.Security.SuppressUnmanagedCodeSecurity()]
[System.Runtime.InteropServices.DllImport(GL.Library, EntryPoint = "glDisableClientState", ExactSpelling = true)]
internal extern static void DisableClientState(OpenTK.Graphics.EnableCap array);

and same function use OpenTK.Graphics.EnableCap, but in docs http://www.talisman.org/opengl-1.1/Reference/glEnableClientState.html the are not EnableCap enumeration used. I think it must be special enum for it or not?

Thanks for work.