Men's Rules? Oh, there are hundreds - I'll try to think of some of them, bearing in mind that it's going to be inherently a very white ethnocentric list;
#1 No Novelty Ties.
#2 No Novelty Socks.
#3 See Rules #1 and #2.
#4 Black Suits are for funerals, waiters and musicians on their way to a gig. And should never be worn with a black shirt unless you want to give off that Hired Heavy/Door Supervisor effect.
#5 Grey suits, blue suits or tweed suits = brown or tan shoes.
#6 Shoes and boots should be chunky or sturdy, not delicate. Unless you're going for a pub lunch, when Dark Brown suede (or clean brown walking boots in the countryside) is acceptable with dark blue jeans, a shirt (not white) and a sweater.
#7 Shiny and checked suits are for used car salesmen.
#8 Unless you are holidaying in the tropics, always choose the heaviest fabric and weave for a suit that you can afford, as it will drape better.
#9 Take that bloody hat off before you walk in the door. And the coat immediately afterwards. Unless you are required to keep your head covered at all times, which is obviously more important.
#10 White sports socks are for tennis, not the workplace. Other colours are for football, rugby, running or the gym. Workplace socks should complement the trousers in tone. If you can't find workplace socks, do not step out from behind your desk at any point - but sports socks are better than no socks at all in that rare disaster.
#11 Shorts should come no higher than the start of the quadriceps muscles and NEVER be made of a shiny, silky type fabric at any length unless you're about to step into the ring for Round #1.
#12 If you haven't got time to iron it properly, don't wear it.
#13 It's better to buy too large and get it altered to fit than too small and look as though you're about to burst out of it like The Hulk.
#14 Your belt is for completing the look, not scaffolding your abdominal adipose tissue.
#15 Skinny cuts are for skinny teenaged boys. If you have a muscular physique, it's better enhanced by a wider cut - especially if you're not a fan of Legs Day - and anybody over 24 will project greater gravitas if they aren't emphasizing twig like limbs.
#16 If there's more scalp than hair, the hair goes unless you have religious or cultural reasons for not doing so; if you do, crack on.
#17 Jackets/Blazers should never have the bottom button fastened.
#18 Shirt cuffs should meet the base of the wrist above the watchstrap, jackets a half inch above that.
#19 Digital watches, especially those with plastic straps or in bright colours, are for children who haven't got the hang of telling the time yet. If you have a smart watch, always replace the strap with a metal or leather one so it looks more like a traditional watch.
#20 Pockets are not for keys, phones, fags, lighters, bus passes, earphones and other paraphernalia of daily life; Men are allowed to have bags now without having doubts cast upon their sexuality (which is damned offensive, by the way) - buy a leather one in a dark colour (not black). The exception is where your wallet and phone (always in a case) fit perfectly in your inside breast pocket without dragging the fabric down - see #8 regarding the weight of fabric.
#21 Novelty cufflinks are the sign that somebody didn't have a clue what to buy you for Christmas and couldn't be bothered to ask.
#22 Trousers should break across the laces.
#23 Coats should be between hip length and just below the knee. And puffas are for moorland expeditions, mountain climbing and watching sport in the depths of winter.
#23a Camouflage gear is for people hunting, shooting, fishing or combating an enemy assailant in accordance with the terms of the Geneva Convention. NOT a trip to a suburban pub or a date.
#24 A baseball cap is not acceptable under any circumstances unless you're about to face a pitcher.
#25 If it's particularly hot and it's been a hard day at the office, carefully fold your shirtsleeves to just below your elbow. Short sleeves are not smart enough.
#26 Glasses and sunglasses frames should never be any colour other than a neutral metal or brown/tortoisehell. You are not Elton John, nor are you the T-1000 Terminator, so mirrored pilot frames are also unacceptable.
#27 It is perfectly acceptable to wear a checked/tartan/plaid shirt at the weekend in a bright colour and rolling up the sleeve is fine, just as it is to wear a T shirt underneath. But no 'amusing' comments or offensive slogans.
#28 Long hair, short hair or no hair. There are no other lengths of hair for white males. Everybody else, it's your hair, wear it exactly how you like.
#29 Unless you have religious or cultural reasons to leave your facial hair uncut, keep it carefully trimmed at all times.
#30 Keep the accessories down to the minimum that meets with your cultural or religious tradition.
#31 Sandals. If you're doing them for some reason beyond getting showered at the gym, it's after regular pedicures. Nobody wants to see black sock fluff in yellowing, thickened nails and half an inch of callused, cracked skin on your heels.
#32 Unless you are a musician who plays particular string instruments or Howard Hughes, you don't need long nails. Clip them.
#33 Clothing and accessories associated with particular cultures, religious belief or practices that are not your own are NOT a means of signalling how quirky, cosmopolitan and well travelled you are.
I think that's probably offended enough people for one night.