- How extensible should the grammar be? Two stakeholders:
reading device manufactuers: predictability/control of behavior
the information: structure/semantics/mediatypes that best represent the content
- How should a document define which extensions it uses?
Reading devices need this information (?).
- What behaviors should be expected from a reading device regarding extended/unknown content types?
- How complex can the extension mechanism be?
To a large extent, this depends on who does the extension:
in a specification phase: complexity a lesser problem
in a production phase: complexity a large problem