Header and frame offer different multiplicity

[martinthomson]

Header and frame offer different multiplicity

[martinthomson]

My initial take here is that one should be plenty and we only allow more than that for a field because we can't really stop people from adding multiple there. I'd prefer to explain that and be done with it.

[LPardue]

Supporting only 1 would work for me, In other specs I've seen what want an Item singleton, they try to accomodate it by saying that any concatenation would look like a list, which is the wrong type and would fail to be parsed - failing closed in this case.

[martinthomson]

Yeah, I don't think that we need to fail closed here. Using SF means that we are outsourcing most of the parsing pieces already, so if we get N, then any one of those N should work. If not then ¯\(°_o)/¯. Potential for harm is minimal.