.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 }
};