Our context is that I'm planning for content migrations in the new Jade namespace, and would like to have a version indicator embedded in or otherwise coupled to our JSON content. This would be helpful at migration time, but more importantly, seems absolutely indispensable for processing old revisions.
We could include a version field in the JSON content itself, but this is a bit of a hack and wouldn't work well for some content formats. My hastily-thought-through proposal is to add a version field to the content table, probably using semantic versioning, though it would also be acceptable to have a single integer which is only incremented for breaking changes.
If others support the idea, I'll go ahead and work the proposal up into something more concrete.
The content model for pages in the Jade namespace may evolve over time in backward-incompatible ways. When we do so, we need a way to introduce newer versions of models without breaking the rendering of existing content.