I have been teaching for 15 years...3 districts (due to DH's job). I have been through all the dress code drama. It is very difficult to enforce. It will totally depend on your principal's ability to do 2 things--1) get all teachers on same page ready to enforce and 2) consequence kids who haven't complied. If these to things aren't in place...forget it NOW
It is very difficult legally to adopt a true uniform code in a public school. You can't require students to buy clothes from one place...like Lands End.
Also...IMO--very strict dress codes are overkill and tend to make high school students react negatively. We had a problem in our school with the three Bs--butts, ****s and bellys. Instead of fixing our regular dress code to address these three evils...we went to a strict dress code. Now, I have to send students to the office for logos on shirts, flip-flops, black pants. Students hate it! I think it is hard enough to get students interested in ancient world history without them thinking we care more about a GAP logo than we do about what we are teaching.