.info is not mandatory. The texinfo distribution itself uses texinfo-1, texinfo-2, etc. It also supports numerous other extensions, mostly for DOS. static char *info_suffixes[] = { ".info", "-info", "/index", ".inf", /* 8+3 file on filesystem which supports long file names */ #ifdef __MSDOS__ /* 8+3 file names strike again... */ ".in", /* for .inz, .igz etc. */ ".i", #endif "", NULL }; static COMPRESSION_ALIST compress_suffixes[] = { { ".gz", "gunzip" }, { ".bz2", "bunzip2" }, { ".z", "gunzip" }, { ".Z", "uncompress" }, { ".Y", "unyabba" }, #ifdef __MSDOS__ { "gz", "gunzip" }, { "z", "gunzip" }, #endif { (char *)NULL, (char *)NULL } };