[Zope] Q: Product adding Properties and Objects

Is there any special syntax for a Zope Product (not a ZClass) to add, say, a File object? context.manage_addFile(id=file_id, file=file, title=title, content_type='application/msword') ..doesn't work. Zope complained about "context". I have seen code that, for a DTML Document, uses "ob = DTMLDocument(data, __name__ = id). Unfortunately, I don't know the corresponding syntax for a File object. Any hints? TIA, Ron