System

System.Configuration

System.Configuration.ApplicationSettingsGroup 
System.Configuration.ClientSettingsSection 
System.Configuration.ConfigurationUserLevel 

System.GC

?? 

System.Guid

System.Guid.NewGuid 

System.IO

System.IO.IsolatedStorage 

System.Management

System.Management.ManagementEventWatcher 
System.Management.ManagementObjectSearcher 

System.ICustomFormatter

System.IFormatProvider

System.IFormattable

[AttributesUsage] attribute

System.AttributesUsageAttribute 

[Browsable(false)] 
public class MyClass 

Specifies how the custom attribute must be used

[Obsolete] attribute

System.ObsoleteAttribute 

[Obsolete] 
public class MyClass 

[ThreadStatic] attribute

System.ThreadStaticAttribute 

[ThreadStatic] 
public class MyClass