Namespaces have been a feature of C# since 1.0 and while you can theoretically have more than one declared in a file it is very unusual and so serves only to cause the rest of the file to be unnecessarily indented.

C# 10.0 allows you to specify a namespace without {} in order to apply it to the whole file and remove one level of indentation.

Code

Now

using System;

namespace MyCompany.MyProduct;

public class EmployeeRepository : Repository
{
    // ...
}

Before

using System;

namespace MyCompany.MyProduct
{
    public class EmployeeRepository : Repository
    {
        // ...
    }
}

Notes

• The file scoped namespace declaration may occur before or after the using statements.

More information

• Specification