Hair long enough to go over any t-shirt collar. Most of the bishops knew about the long hair before calling me. My wife doesn't like beards, so I have rarely had a beard. I also don't really enjoy beards.
Requiring students to sign an agreement to obey commandments, live within the temple recommend structure totally makes sense. Holding students to a higher law makes no sense. Creating a framework that would likely have excluded Jesus and most or all of his ancient church apostles, the 3 Nephites, the 12 disciples called by Jesus in the Book of Mormon and at least 6 of 7 of the first 7 modern prophets from attending BYU is definitely pharisaical, weird, odd...
I agreed to the code and honored that as a student. Had a BYU student ID card with a picture taken before I started at BYU for most of my time at BYU with hair that was well over my collar.