Overtime and breaks...
I worked at one place that was very informal, people just took breaks as needed and nobody was watching the clock. They had no provision for overtime, but like if I was in the middle of something at the end of the day I'd stay in 5 or 10 minutes to finish it.
I worked at another place (as a temp, for about a week..), they considered the 30 minute overtime and two 15 minute breaks to be concurrent (i.e. no breaks). You should have seen how both the temps and permanent employees rushed the door, At 4:59:50 people started rushing the door so they could get there first and get out at exactly 5, there was some pushing and jostling for position. Then they'd like run out to the parking lot and jocky for position in their cars to get to the exit first. I'd wait until 5:01 just because I didn't need any of that business. Then, ironically, after all that racing, the road outside their place has a 45MPH speed limit and these people who just raced for the exit would be going like 25, so I'd end up passing like a dozen cars that had just raced for the exit a minute ago.
But yeah, reclassifying employees so they cut their pay with available overtime pay as compensation, then not allowing the overtime to be logged? That's straight up wage theft, hopefully IBM gets taken to the cleaners for this.