For more information on this topic, you can refer to the .NET Framework guidelines included in the .NET Framework SDK documentation under .NET Framework Developer Specifications\.NET Framework Design Guidelines\Naming Guidelines.
Use your company or product name, and employ mixed casing with an initial capital letter-for example, Microsoft. If you're in the business of selling component software, create a top-level namespace that is the same as your company name and then for each product, create a nested namespace with its embedded types, which will prevent name collision with other products. An example of this can be found in the .NET Framework SDK: Microsoft.Win32. This strategy might result in more long-winded names, but remember that the users of your code need only specify the using directive to save typing. If your company is called Trey Research, and you sell two products-a grid and a database-name your namespaces TreyResearch.Grid and TreyResearch.Database.