Ha I'm surprised no one mentioned one of the most common name maltreatment complaints. The Gaelic patronymic prefix Mc/Mac.

When treating Mc/Mac names, the first letter after the prefix is always capitalised.. e.g McDonald's, McCarthy, McCain, McCoy, McConnell etc but you're more likely to see mcdonalds, mccoy, mcconnell.

Orthographic case preservation reports were like the biggest complaints that no one was interested in fixing during a short stint in the airline industry.

That and hyphenated names.