In German you have the same, only within one language. ß can be written as ss if it isn't available in a font, and only in 2017 they added a capital version. So depending the font and the unicode version the number of letters can differ.
"Traditionally, ⟨ß⟩ did not have a capital form, and was capitalized as ⟨SS⟩. Some type designers introduced capitalized variants. In 2017, the Council for German Orthography officially adopted a capital form ⟨ẞ⟩ as an acceptable variant, ending a long debate."
I don't see why it should. I also believe parent is wrong as there are unambiguous rules about when to use ß or ss.
Never thought of it but maybe there are rules that allow to visually present the code point for ß as ss? At least (from experience as a user) there seem to be a singular "ss" codepoint.
>also believe parent is wrong as there are unambiguous rules about when to use ß or ss.
I never said it was ambiguous, I said it depends on the unicode version and the font you are using. How is that wrong? (Seems like the capital of ß is still SS in the latest unicode but since ẞ is the preferred capital version now this should change in the future)
> How is that wrong?
Not sure where, how or if it's defined as part of Unicode, but so far I assumed that for a Unicode grapheme there exists a notion of what the visual representation should look like.
If Unicode still defines capital of ß as SS that's an error in Unicode due to slow adaption of the changes in the German language.
That's not really any different than the distinction (or lack thereof) between "ae" and "æ". For that matter, in Russian there is a letter "ы" which is historically a digraph consisting of two separately letters "ъ" and "i" that just happens to be treated as a single letter for so long that few people would even recognize it as a digraph. This kind of stuff is all language-specific, which is why for Worlde etc you always need to be aware of the context, and this context will then unambiguously decide what constitutes a single letter.