There is certain friendship which is called Brotherhoodly friendship and sometimes we call those friends as Bro. I came across this list of codes and it very much makes sense. If this code is followed religiously no friendship in the would would have broken;

1. Bros before hoes – Your bros are your bros and that’s final. They know and follow the same code that you do. They’ve been around, sometimes, since you were little kids and there’s no reason why a girl should continuously break that bond.
2. Never bang your bro’s sister, mom, or ex – These chicks are off limits. No matter how hot they may be it’s just asking for trouble and in the end you’ll probably end up with nothing.
3. You are obligated to be a wingman, if asked – You’d expect your bros to be your wingman when asked, therefore you must return the favor. We must help each other get laid, otherwise we’re doomed.
4. Take one for the team – If your bro is hitting it off with a chick and her friend is being an obstacle then it is your job to bang that obstacle no matter what she looks like. Ok, you don’t necessarily have to bang her but at least keep her occupied. That’s all we ask for.
5. Be the bearer of bad news if you catch your bro’s girl cheating – Don’t play dumb and let your bro’s girl play him for a fool. If you catch his girl cheating you need to let him know. It’s his right to know these things and it’s your job to be looking out for him.
6. Never use the stall next to another guy unless there is no other stall available – I don’t think I need to explain this one.
7. It is your responsibility to help a bro move – Don’t leave your bro hanging. Have you ever tried to moving everything by yourself? It sucks, and chances are you’ll need to ask your bros for the same favor, eventually.
8. A bro should never disclose the sexual history of another bro to a chick – Most girls don’t like guys that have been around. Others like a guy with a little experience. It’s not your job to figure out which one of these girls she is. Just play dumb and avoid the question.
9. A Bro never publicly reveals how many chicks he’s banged – Nobody really cares how many chicks you’ve banged and it only makes you look like you’re seeking attention. The only exception is if you’re known for getting around and even then you don’t state specific numbers.
10. If a bro asks another bro to keep a secret, he shall take that secret to his grave. This is what makes them bros, not chicks – Guys don’t gossip. That’s just the way we are. We don’t call around to all our friends and start sending mass text messages whenever we get a bit of information out of one of our bros. We keep it to ourselves.

These are just top 10 codes and there are 140 more codes written by  Barney Stinson. If i post all 140 it might become copyright infringement. So, i’d recommend you all to read all 150 codes as it really makes sense.