Comfortable underwear

• Old rule: tightly laced corsets do not have permanent negative effects on the health of women who wear them. They still have temporary negative effects, such as limited breathing.

(In addition to preventing physical problems, this will also prevent corsets from going out of fashion in the 20th century, without necessarily adding a rule "women always wear corsets".)

• New rule: a combination of a pushup bra or tightly laced pushup corset, and a thong wedged as high up the ass as possible (either separately, or as part of a single one piece garment), is the most comfortable thing for any woman to wear under her clothes, and without any other clothes is the most comfortable thing to wear for sleeping or physical exercise.

And for something slightly different:

• Old rule: 50% of women find sleeping with their hands bound to be extremely comfortable, the more restrictive the binding, the better.