BFMP is a method for naming conformations of six-member rings.  It is similar to the IUPAC method (that, e.g., uses ¹C₄ for one of the chair conformations), but it is more flexible.  It is able to unambiguously name symmetrical and asymmetrical shapes.  It can also give information regarding the degree to which a shape deviates from symmetrical.  You can download free software that will identify the shapes for you.  For more information, see the download page and the article below that provides a detailed explanation of the naming system.