The Natural Bears Classification System (NBCS) is a set of symbols using letters, numbers, and other characters commonly found on modern, Western computer keyboards. It is used by gay and bisexual men who self-identify as "bears". These codes are used in email, Usenet, and Internet forum postings to identify the physical type and preferences of the poster. The code was developed by Bob Donahue and Jeff Stoner. The NBCS is also called the "bear code". 