The Aryan Brotherhood of Texas (ABT) is the largest white supremacist prison gang in Texas and possibly in the United States. It is also one of the most violent, having committed many murders. It is active both behind bars and on the streets across Texas and in neighboring states. Despite its name, the ABT is a group separate from and independent of the "original" Aryan Brotherhood, which is present primarily in the California and federal prison systems.
Because of its size and age (it dates back to the 1980s), the ABT has evolved a variety of tattoos, both open and coded. The standard ABT "shield" or "patch" is a shield-like image with a sword and a swastika inside the shield and the gang's initials on the outside. However, many ABT members may not have this tattoo. Among coded tattoos, the most common is use of the number 12 (or the numbers 1 and 2), which are numeric substitutions for the letters AB.