Today I stumbled over a framework v1.1 issue related to the wellknown System.Collections.Specialized.NameValueCollection. I used it in a public interface as a return parameter and somewhere again as method parameter within a assembly marked with the attribute CLSCompliant(true). The MSDN docs are silent about CLS compliance in that case and I figured out, it is not compliant! Got compile errors like this:

ADSIAuthenticationProvider.cs(31,37): error CS3001: Argument type 'PROCOS AG.Components.Authentication.Shared.IAuthenticationConfiguration' is not CLS-compliant

or