RISC OS filetypes use metadata to distinguish file formats. Some common file formats from other systems are mapped to filetypes by the MimeMap module. Such mapping was previously handled by DosMap. The MimeMap module maps RISC OS filetypes to and from MIME content types, dotted filename extensions and Apple's Uniform Type Identifiers. Requests for new filetype allocations for all RISC OS versions are handled centrally by RISC OS Open.