My criterion is that paths should not be painful to type, parse, or copy-paste. So no keyboard layout switching, and escaping should not be necessary. Lower-cas

My criterion is that paths should not be painful to type, parse, or copy-paste. So no keyboard layout switching, and escaping should not be necessary. Lower-case Latin letters, digits, periods, and dashes (of the unique variety that's available on keyboards, and not in the initial position) are simple and enough.