.NET: with respect to AssemblyVersion, what defines binary compatibility?

Question

What changes to a strong-named assembly necessitate a change in AssemblyVersionAttribute? Clearly, changing the public api in a way that could require a client to have to make a

Answer 1

Microsoft adds new methods/classes in .NET libraries in service pack releases without changing AssemblyVersion (still 2.0.0.0 / 3.0.0.0). Microsoft only changes the AssemblyFileVersion. For example, In .NET 2.0 SP1, DateTimeOffset struct was added.

Should this practice be recommended to us because Microsoft do this? It is confusing.