@silverpill @darius forgive me for being so relentlessly editorial but maybe there is a practical outcome of this discussion, like a style guide or terminological/editorial convention that could be mentioned in the FEP-a4ed? i agree that there are stages of adoption and "seamlessly extends without breaking federation or degrading UX for users of other implements" is a property worth naming (and perhaps even requiring of FEP-defined extenions!)