Fonts

ttf otf ttc otc woff woff2 pfb pfa cff

A font file opens as its glyphs, a row each: the glyph's number, its name, the Unicode character it draws, how far it advances the pen, and how many contours and points its outline has. The app reads the outlines itself, so no font has to be installed to look inside one.

Format	Extensions
TrueType and OpenType	ttf otf
Collections	ttc otc
WOFF and WOFF2	woff woff2
PostScript Type 1	pfb pfa
Bare CFF	cff

Which of these a file is, its first bytes decide, not its name. Structure mode lays out how it is put together: the table directory of a TrueType or OpenType font, the compressed tables of a WOFF, the table directory and Brotli stream of a WOFF2, the indexes of a CFF, the segments of a Type 1 font. A WOFF2 that holds a collection shows its structure, but not its glyphs.

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