Where are the mandatory rules posted for using jack stands, etc.?

[larrybard]

betegh9 wrote:

when I am just changing tires (wheels), I just jack up the car's corner and swap wheels out without getting under it. If I get under it, jack stands for sure. At the track, I only check tire pressures. Do all the necessary dirty work in my garage.

Hmm . . . maybe I'm reading too much into some of the posts, but there seems to be a difference of opinion as to whether it's important that jack stands be used when only changing a tire.