CMX/BCF is a format for data on the inhabitants of the world of The Sims. It can be stored in text (CMX) or binary (BCF) formats. The BCF version usually has a dual file extension
.cmx.bcf. It has three data sections, referred to as "skeletons", "suits", and "skills"; this refers to the bone structure of the character, what is on top of the bones (skin), and what actions the character does. The skills section includes references to animation data contained in CFP files.