Filename character set and its interpretation shall be controlled per directory or, at least, per FS. This pertains not only to permitted set like with or without LF, but to collation rules as well (including case insensitivity with cases like Turkish/Crimean/etc. I/ı and İ/i). Also this shall include workarounds for already existing problems: if a directory already contains files I1 and ı1, there shall be a technique to deal with them separately ever with Turkish locale.
But restricting this at syscall level is definite insanity, among with excuses.
But restricting this at syscall level is definite insanity, among with excuses.