
The three dots tattoo is a very common prison tattoo that symbolizes ‘mi vida loca’ or ‘my crazy life.’ It doesn’t symbolize any particular gang, but rather the gang lifestyle. It’s typically found on the hands or around the eyes.
The three dots tattoo can also carry some religious significance, representing the holy trinity.

1488 can be found on the tattoos of white supremacist/nazi inmates.
14 represents 14 words. The 14 words are a quote by nazi leader David Lane: “We must secure the existence of our people and a future for White Children” The 88 is shorthand for the 8th letter of the alphabet twice, HH, which represents Heil Hitler.

The five dots, sometimes known as the quincunx, represents time done in prison. The four dots on the outside represent the four walls, and the dot on the inside represents the prisoner.
The five dots is actually an international prison tattoo; it is common among both American and European prison inmates. The five dots are typically tattood on the prisoner’s hand between the thumb and forefinger.

In some places a teardrop represents a long prison sentence, in other places the teardrop represents that the bearer committed a murder.
Sometimes the teardrop is empty. This can symbolize an attempted murder, or that one of the inmate’s friends was murdered and that they are seeking revenge.

ACAB is an acronym very commonly found inked on the bodies of British prisoners. It stands for All Cops Are Bastards.
Some with the tattoo claim that ACAB stands for ‘Always Carry A Bible’, but it’s widely believed that these are just people who regret their decisions or are trying to make a good impression.
Via Likes which has many more examples of prison tattoo meanings, particular various associations with specific gangs.