You probably have to explicitly exclude the environment of external methods,
Why do you say that?
As I can basically access and modify anything from an external method (thanks to Python power), you must either define very clearly what I'm allowed to do, or decline any assurance that it will work in any future release. Of course I have some (hopefully good) idea about what I can do from an external method without breaking things in the future, but since this is not a compiled (aka, locked & sealed) environment, I think you have to exclude it. This applies to external methods and writing of products, but not to TTW use of Zope's facilities (including scripts). Even if I test and report it, you may rightly say that I shouldn't have "touched" that part in the first place. Martin