Floppies
I said I was showing my age!
Home computers used cassette recorders when I started. No direct access to data at all. And the big computers used rooms of reel-to-reels. This wasn't just backup either. Internal storage was purely temporary and was wiped when you turned them off.
8" were a modern luxury and then they went down to 5 1/2" before someone decided that we were taking the "floppy" thing too literally and needed to put them in the hard case versions.
But I digress ...
The problem was that with a restricted character set, there was a very basic set and some extra numbers that were used for different things in different countries. When they stored them in larger units the higher end could be packed with zeroes for the standard set, mapping to exactly the same number (like in dates, 1/7/1882 is the same as 01/07/1882), the other numbers had/have a code in front to denote which set they were/are representing at the time.
I presume the  is the one used to denote the extra British character set and appears when anything belonging specifically to that set is used in contexts that can't use it properly. The same number in the American char. set was mapped to to the dollar sign and for a long time it was very common when using a British keyboard, to type pound and have it appear as dollar because the keyboard is independent of the software so just transferring numbers. The teletype printer
had to have the right software (or more likely hardware) too, to know that you meant pound.
By the way, different "natural" languages have different numbers of graphemes (characters) in their alphabets so, apart from the order they appear in, in words, there is a lot more than just mapping to a different shape, to getting the same commands to come out right at the top level.