Their letters are equivalent, sharing the same names and alphabetical order and all three are unicameral (make no distinction between upper and lower case).
en.wikipedia.org Spelled with a lower case o, or "oberst", it is an adjective, meaning top, topmost, uppermost, highest, chief, head, first, principal, or supreme.
en.wikipedia.org Sometimes only vowels are upper-case, at other times upper and lower case are alternated, but often it is just random.
en.wikipedia.org Numerals and symbols are at the top, lower case, punctuation and variable width spaces on the left, and capitals are on the right.
en.wikipedia.org