The problem I see with "klass" is that you can't easily talk about it to another developer. e.g.: "Make sure you set the class-with-a-k property to 'alien'."

The problem I see with "klass" is that you can't easily talk about it to another developer. e.g.: "Make sure you set the class-with-a-k property to 'alien'." "Make sure you set the type property to 'alien'."