Caret traversal should stop at external and internal element boundaries

[paperboyo]

In Chrome it’s possible to traverse the caret via keyboard through all this:

While it may seem useful at first:

• I’m not sure it’s actually correct
• doesn’t happen in Firefox

I think tab should be the only way to get to the next editable “island”. Some apps use Alt+Enter, but not sure about that.

Something to ponder if nothing more. At least the inconsistency between the browsers should not happen.