NM cable under joists.

[mjf]

Even notching does not solve the bigger risk: which is people hanging things from the wires. And as other's noted, a notch on the bottom side of a load carrying horizontal joist is the absolute worst place to have a notch. A hole weakens the joist a lot less.

One of the most ridiculous codes in the book. Drill holes and move those cables up 1 1/4" and a force field magically repels any object trying to be hung from them.