What words will mean things in the context of various representations? How will they form sentences that get things done? If each representation has its own markup how will these expressions influence representations outside their realm of discourse.
Pages within overlapping sites cooperate as equals within the user's browser.
Explain how representation specific adjustments can be made by ad-hoc changes expressed in a fit-for-purpose markup, a kind of domain specific language.
Explain how markup captures the details of work in progress and thus facilitates replication, confirmation and evolutionary improvement of technique.
Explain how powerful markup makes federated wiki a place to do work, not just a place to talk about doing work.