Specify validation for new features

[jkup]

We don't want to break backwards compatibility, so we have agree to never do things like codify into the spec that version has to be the integer 3. I think we all agree on that?

We should discuss if we want to begin introducing "validation" text to the specification for new features. For example, with Scopes, should the specification text say that GeneratedPosition must only contain a line and column and they both must be numbers?

I just want to kick of a discussion about how much we add "validation" language to the specification for new features.