Way back when, I don't recall ( I should) but the American Motorcycle Association AMA, made a statement that " 99% of all motorcycle riders are nice people" The outlaw motorcycle clubs/gangs adopted this as a "Badge of Honer" saying that they were the other 1%....as time passed most outlaw motorcycle club/gangs started wearing a "1%" patch signifying that they were outside the AMA and other laws....thus the 1%er was born.
The term 1%er still notes these rider/bikers as outlaws in the motorcycle world. As stated, some f the most notable ones are; Hells Angles, Outlaws, Bandidos, Pagans, Iron Horseman, Mongols, Sons of Silence...and many puppet clubs of the major players.
Most if not all, wear a "three piece" patch or "colors" as their called...rocker at the top and center patch and a rocker at the bottom...most other motorcycle clubs, such as Harley Owners Group ( HOG, Southern Cruisers, Christian Motorcycle Association etc.) wear only a two or one piece patch, top rocker and a center patch with no "MC" patch on their vest....the only exception to this "rule" is the Blue Knights.
The Blue Knights are a Law Enforcement motorcycle club that wears a three piece patch, but the international vest or colors are a light blue, opposite of the black vest the outlaw clubs wear. Some do wear a black vest with the BK colors and is acceptable now, but the official color is light blue.