Once considered a fashion “don’t” in menswear circles because of their association with dweeby accountant types and Lewis and Gilbert in “Revenge of the Nerds,” short sleeve button-ups have shed their F-grade stylistic reputation in recent years and emerged as current and fresh summer must-haves. Designers and tastemakers overturned the old longstanding fashion rule of “if you want short sleeves just roll up your long ones” several seasons ago and these arm-revealing tops are now considered key pieces for today’s sharply dressed man. As designer Robert James of By Robert James recently told me: “I would say that if you don’t have a short-sleeved shirt in your wardrobe, get it done. A few years ago it had to be rolled up but now, no.”