text: This IFF was adopted by a number of developers including Apple for AIFF files and Microsoft for RIFF files (which were used as the basis for the AVI and WAV file formats). Apple referred to many of these codes as OSTypes. Microsoft and Windows developers refer to their four-byte identifiers as FourCCs or Four-Character Codes. FourCC codes were also adopted by Microsoft to identify data formats used in DirectX, specifically within DirectShow and DirectX Graphics.
  In Apple systems
  Since Mac OS X Panther, OSType signatures are one of several sources that may be examined to determine a Uniform Type Identifier and are no longer used as the primary data type signature. Mac OS X (macOS) prefers the more colloquial convention of labelling file types using file name extensions. At the time of the change, the change was a source of great contention among older users, who believed that Apple was reverting to a more primitive way that misplaces metadata in the filename.
  Filesystem-associated type codes are not readily accessible for users to manipulate, although they can be viewed and changed with certain software, most notably the macOS command line tools GetFileInfo and SetFile which are installed as part of the developer tools into /Developer/Tools, or the ResEdit utility available for older Macs.