Soul Class System

The Soul Class System (霊等級方式, Reitōkyū Hōshiki; literally "Method of Soul Grades") is a classification system utilized by the to properly identify. This is often utilized primarily to assess the level of danger that a Ryoka might present or the degree to which their abilities may serve as useful to the Soul Society. Despite being meant for Ryoka, the system bases its levels on the strength of its own military might and uses the as a measuring tool for the system. The Soul Class System is also used to classify and certain  with supernatural abilities as well.

B-Class
Otherwise known as the "Captain class" (隊長の戦闘力, Taichō no Sentō Ryoku; literally "Combat Power of a Captain"), this is the level at which the Captains of the are said to average out.

Behind the Scenes
This system was inspired by a similar ranking system used in the anime and manga series, Yu Yu Hakusho.