title: Adding -Ex to the name of a type in .Net
body: <p>I've noticed a pattern recently in our codebase at work, where most of our model class have a name such as User, and there is an inheriting type that has extra fields on it called UserEx.  I've also noticed this in the C# async CTP where they put the additional static methods for Task in a class called TaskEx (due to technical restrictions, since they couldn't alter the existing library).  Talking to someone at work, I learned that -Ex classes exist to optimize network transfers (you can pull only the bare minimum if you need).  My question, then, is what does -Ex stand for?  The only thing I can think of is possibly "Extra". </p>