It's been a few years since I've done one, and we did them ad-nauseum in aersopace college of course but a given manufacturer submits a "VN Diagram" for a new airplane design to the FAA or their designate which must be approved. V stands for velocity in feet per second, and N is load factor. It looks like the ones you see in pilot textbooks, but with a gust envelope added as well, see diamond shaped envelope shown in this one: