Acorn Font files are the native format for fonts on RISC OS. Each file contains data that describes aspects of a particular typeface and weight, describing each glyph using either a vector representation (an outline font) or a bitmap. Fonts are used for on-screen rendering and printing.
Outline fonts are described by two separate files: IntMetrics and Outlines. The IntMetrics file contains information about the sizes and shapes of each glyph, kerning and basic styles. The Outlines file contains definitions of the glyphs.
Character encoding files describe the mapping between character numbers and the glyph definitions for each font.