This document attempts to provide useful and pragmatic guidelines for programming in C# 3.0 which we at Aviva Solutions already use in our day-to-day work. This idea started in 2002 when Vic Hartog (Philips Medical Systems) and I were assigned the task of writing up a coding standard for C# 1.0. Since then, I've tried to publish a similar document for C# 2.0, but because of a change of employer, I never officially published it other than through blog posts. In the last couple of months I’ve received several requests from the community for an updated version of this document, preferably covering C# 3.0 as well. Moreover, I have become particularly fond of the power that Visual Studio's Code Analysis (FxCop) provides.