Identifiers should not contain underscores
Breaking - when fired on assemblies
Non Breaking - when fired on type parameters
By convention, identifier names do not contain the underscore (_) character. The rule checks namespaces, types, members, and parameters.
Naming conventions provide a common look for libraries that target the common language runtime. This reduces the learning curve required for new software libraries, and increases customer confidence that the library was developed by someone with expertise in developing managed code.