But to the OP's point, mechanics do this all the time and they don't refer to every car's manual. They look under the car and they immediately recognize where you can place the jack safely. How can one tell where it's safe to place a jack without having to read the manual?
Some cars have obvious jacking points, an Audi 5000 had rubber pads built in the right spots, my 911 has holes in the side you slide a device into and jack up the whole side by.
Many cars have small notches for the OE jack to fit in, line those up with the pads in a way that won't bend sheet metal and you're good. (This is where the puck rrocket mentioned is used)
Quite often you use suspension pickup points to jack from, I use a rear crossmember to lift the entire rear of my Audi 90.
Eventually mechanics know where the points are on popular models, others they either check the manual or guess, usually they get it right.
