A Mechanic for additional Character Personalisation in WFRP II
from the introduction:
Quirks function as additional special qualities that describe a character in much the same way as Talents and Traits. Unlike Talents, Quirks are a freeform system of brief phrases or descriptors that summarize a notable quality or special ability of the character. These qualities could be associated with the characters race and career, or a linked to the character’s achievements, reputation or even ancestry.