Namespace-only class visibility in C#/.NET?

Question

In C#, can you make a class visible only within its own namespace without living in a different assembly? This seems useful for typical helper classes that shouldn\'t be use

Answer 1

If you have a single assembly you can define as many namespaces in that assembly as you want but no matter what modifier you apply in the IDE you will always be able to see the classes in other namespaces.