For implementing declare @type interacting with declare @parents during compilation - we need to be able to add an annotation to 'binary type binding' (this is how types are seen during incremental compilation). Unlike a SourceTypeBinding - a BinaryTypeBinding does not allow easy interaction with its annotations - so what we do is take the eclipse annotation, suck out the name/signature and visibility and put that information in a 'FakeAnnotation'. The FakeAnnotation is attached to the BCEL delegate for the binary type binding - this will allow type resolution to succeed correctly. The FakeAnnotation never makes it to disk, since the weaver does the job properly, attaching a real annotation.