Notify users when an obsolete method is being used.
From http://www.developer.com/net/top-10-tips-for-c-programmers.html
// This will only provide a warning
[Obsolete("This method will be deprecated soon. You could use XYZ alternatively.")]
public void MyComponentLegacyMethod()
{
//Here is the implementation
}
// This will cause some kind of error
[Obsolete("This method will be deprecated soon. You could use XYZ alternatively.", true)]
public void MyComponentLegacyMethod()
{
//Here is the implementation
}