A rating system used to classify an employees level.
The highest level is shitheads aka bosses.
Mid levels are asskissers aka upper management and brownosers aka lower management.
Lowest level is shitshovellers aka hardworkers.
According to the shitscale at work the shitheads go golfing while leaving the asskissers and brownoser in charge of the shitshovellers.
One who calls attention to problems peopledon't want to talk about, often in a fashion that offends others. Connotes a degree of righteous indignation or "uncomfortable truth".
"Dude's a shitcaller, but you have to admit he has a point."