> "Don't break the web" is a hard constraint. Any solution you propose that violates this constraint is unacceptable. What would you rather happen with mangled

> "Don't break the web" is a hard constraint. Any solution you propose that violates this constraint is unacceptable. What would you rather happen with mangled input like opening tags with no ending tag? Should the browser always try a best effort and never die with errors? Perhaps we can afford to break some things even though we can't afford a clean break? I think you'd agree that the perfect is the enemy of the good. I'd argue that perfect backward compatibility is the enemy of good backward compatibility as well. Thoughts? I'm unwilling to accept this is a hard constraint. It can't be that a later version should accept all inputs accepted by an earlier version. We should carve out exceptions based on what's actively used and inform the developer that what they're using is bad code. Eventually, some day if it becomes rare, we can discontinue support.