I suspect that definitive rules would be impossible to provide unless they were draconian. I would imagine that the target audiences of this latest advice are the people who have routinely ignored earlier advice about social distancing in particular, e.g younger pub and party-goers and certain social family groups. Yes, we can all find examples that seem incongruous but my own observations on public transport are that they are not running anywhere near capacity generally and from what I hear most offices seem to be able to provide reasonable space and the necessary precautions. In the end its about reducing risk rather than eliminating it I guess.
The worrying trend among the young is the belief that a, the problem doesn't apply to them and b, that the consequences for others that they may have contact with are totally over exaggerated. Conspiracy theories abound on their social media. The latest 'generic' guidance is more likely to make them think about how they go about their social lives and make transgression easier to spot.
It is pretty obvious from statistics that the basic measures do work when people apply them and those who have adopted a common sense approach rather than demanding clearer rules have benefitted from their actions with lower infection rates.
