My rule is this: it must validate unless you have a good reason for it not to.
When I develop I use a firefox addon http://users.skynet.be/mgueury/mozilla/ that automatically tells me how many validation errors I have (it runs the validation locally).
So as much as possible my code validates, but sometimes it doesn't - but each time, there is a reason for it, and it's not just an accidental mistake.
When I develop I use a firefox addon http://users.skynet.be/mgueury/mozilla/ that automatically tells me how many validation errors I have (it runs the validation locally).
So as much as possible my code validates, but sometimes it doesn't - but each time, there is a reason for it, and it's not just an accidental mistake.