Re: Standardisation is always welcome
> Backslash was used to maintain compatibility with the 1.x option delimiter.
And the MS-DOS 1.x option indicator ('/') came from CP/M which MS-DOS is a clone of, and that came from CP/M's origins, being written on DEC machines with RT-11 or similar.
When MS tried to make a 'family' of operating systems with Xenix and MS-DOS 2.0 they had to cope with the conflicts between DEC originated systems (CP/M, MS-DOS) and Unix, and did that poorly.