During college, about 90 percent of an editing class I took was about learning the Associated Press Stylebook.
It’s important, for some reason, that journalists consistently describe a carbonated drink as soda, not pop, and that Minnesota is abbreviated Minn., not MN.
Which brings us to busing and bussing.
Microsoft Word underlines “busing” as if there were something wrong with it, but the AP Stylebook says it’s the proper way to spell that verb form of transportation vehicle.
Why not “bussing?” Because that means kissing.
See also: buses/busses and bused/bussed.