OS X / macOS 10.x supports a wide variety of font formats. It supports most of the font formats used on earlier systems, where the fonts were typically stored in the resource fork of the file. In addition to the data-fork version of TrueType and the Adobe/Microsoft OpenType fonts, OS X also supports Apple's own data-fork-based TrueType format, called data-fork suitcases with the filename extension . Data-fork suitcases are old-style Mac TrueType fonts with all the data from the resource fork transferred unchanged to the data fork. The system also supports the instances created using the "multiple master" PostScript variant.