ref: 51d7d3eb6aee563d489f52258f6bc16d43cc50de
dir: /sys/src/libflate/zlib.h/
/* * zlib header fields */ enum { ZlibMeth = 0x0f, /* mask of compression methods */ ZlibDeflate = 0x08, ZlibCInfo = 0xf0, /* mask of compression aux. info */ ZlibWin32k = 0x70, /* 32k history window */ };