The contract clamps down on areas of alleged abuse by the union, including the entitlement to sick pay. Whereas controllers have, in the past, self-certified their medical fitness on a day-to-day basis, in addition to the mandatory medical checkups, the new rules appear to require supervisors to judge whether a controller can get through a shift. The union says safety will be compromised by forcing controllers to work when they say they don't feel well or are too tired to. Another change apparently does away with the usual break after two hours on position. But perhaps what rankles controllers most, on a personal level, at least, is the formal dress code being introduced. Some controllers dress as if they work in windowless rooms where visitors aren't customarily allowed but FAA brass have apparently had enough of flip flops, tank tops and cutoffs. As of Sunday, the glow of the screens will reflect off, as we understand it, collared shirts, dress slacks and shoes and socks. But it's not like they'll be able to show off their new-found nattiness. Another rule apparently bans controllers from leaving the facility during their shift.