Oh, you can do far more than "code pages of sorts". Unicode has a variety of metadata available about each codepoint. The things that are "code pages of sorts"

Oh, you can do far more than "code pages of sorts". Unicode has a variety of metadata available about each codepoint. The things that are "code pages of sorts" are maybe "block" (for ö "Latin-1 Supplement"), and "plane" (for ö it's "Basic Multilingual Plane"), but those are really mostly administrative and probably not what want. But you also have "Script" (for ö "Latin). Some characters belong to more than one script though. Unicode will tell you that. Unicode also has a variety of algorithms available already written. One of the most relevant ones here is... normalization. To compare two strings in the broadest semantic sense of "are people likely to consider these the same", you want want a "compatibility" normalization. NFKC or NFKD. They will for instance make `1` and `¹`[superscript] the same, which is definitely one kind of "consider these the same" -- very useful for, say, a search index. That won't be iron-clad, but that will be better than trying to role your own algorithm involving looking at character metadata yourself! But it won't get you past intentional attacks using "look-alike" characters that are actually different semantically but look similar/indistinguishable depending on font. The trick is "consider these the same" really, it turns out, depends on context and purpose, it's not always the same. Unicode also has a variety of useful guides as part of the standard, including the guide to normalization https://unicode.org/reports/tr15/ https://unicode.org/reports/tr15/ and some guides related to security (such as https://unicode.org/reports/tr36/ https://unicode.org/reports/tr36/ and http://unicode.org/reports/tr39/ http://unicode.org/reports/tr39/), all of which are relevant to this concern, and suggest approaches and algorithms. Unicode has a LOT of very clever stuff in it to handle the inherently complicated problem of dealing with the entire universe of global languages that Unicode makes possible. It pays to spend some time with em.