A guide for people making the decision for the first time.
The rules are not new. What is new is how many people they now apply to.
Where to go from here
The exceptions matter more than the rule, and there are three of them. Nobody is required to explain this to you, which is half the problem.
The exceptions
The exceptions matter more than the rule, and there are three of them. The practical effect is easier to see in a single example than in a summary.
The short answer: check the date, then check the figure, then decide.