Thanks to Beth Shepherd for alerting me to the Design Police (2022 note: the link has disappeared). It's obviously hit the spot because it's on practically every design blog - and has revealed one or two sense of humour failures, judging by some of the comments.
*The Design Police are Stephen Woowat and Karl Goldstraw.
I wonder if this doesn't represent a real insight into simple, engaging ways to represent good practice. Having said that, each rule invites the question 'why', and the answers would range from legibility research to simple 'nice boys/girls don't do that'.
For example, using inch marks for quotations doesn't actually do anyone any harm, but it is a signifier of competence that people will judge you by – like using the wrong knife at dinner.
Inspired by the Design Police, I'm now speculating about repurposing road signs (not original, I know) to warn readers of problems ahead in complex writing. Here are some signs whose meaning I hope is clear: