And finally assembly-relevant attributes in the System.Runtime.InteropServices. For those that are in the unfortunate position of having to do interop in production (I have been there myself!)

AutomationProxyAttribute: Specifies whether the type should be marshaled using the Automation marshaler or a custom proxy and stub.
ComCompatibleVersion Indicates to a COM client that all classes in the current version of an assembly are compatible with classes in an earlier version of the assembly. This attribute can be applied to assembly, namespace and class level.
ComVisible Controls accessibility of an individual managed type or member, or of all types within an assembly, to COM.
DefaultDllImportSearchPathsAttribute When applied to an assembly, this attribute specifies the paths that are used by default to search for any DLL that provides a function for a platform invoke, in any code in the assembly.
ImportedFromTypeLib Indicates that the types defined within an assembly were originally defined in a type library.
[PrimaryInteropAssembly] ( Indicates that the attributed assembly is a primary interop assembly.
TypeLibVersion Specifies the version number of an exported type library.