ARRANCAR RANKS

Espada ( spanish for sword ) the most powerful arrancar in Aizen's army. Each Espada is given a Number (from 0 to 9) as their rank when they are created. That Number is relative to the Espada's combat ability and power level. This number is tattoed somewhere on their body (Noitoras' on his tongue, for example).Espadas are given suburdinates called fraccion.

Privaron Espada ( spanish for Deprived Sword ) Former Espada who lost their ranks because of the arrival of more powerful Espada Which was created by Aizen using the Hougyoku.Privaron Espada are assigned a three digit number and resides in Tres Cifras which literally translated as "three digits"

The Números are assigned a two digit number at birth from 11 to 99 to indicate their age (the number 11 is the oldest, number 99 is the youngest). The main number uniform consists of a white-collared jacket and robes held with a black ribbon. However, the uniform is customizable, giving each number a sense of individuality. The fighting ability of Números is considered superior to all other arrancar, except for swordfish (current and past). The strongest Números is selected by sword into their Fracción.

Exequias
They are responsible for dealing with intruders and Rebels in Las Noches, usually terminating as with their names. They are the equivalent of Soul Society's Onmitsukidō.