This particular question is not about the origin of README files (the earliest documented is from 1974 on TOPS-10) but about why README remains upper case on mi

This particular question is not about the origin of README files (the earliest documented is from 1974 on TOPS-10) but about why README remains upper case on mixed-case systems (e.g. Unix). Neither has anything to do with MS-DOS. ASCIIbetical order is a good answer (certainly the reason I named things that way) although it doesn't entirely explain README over ReadMe.