Wikipedia:Reference desk/Archives/Computing/2016 November 12

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November 12

˜

What's the point of having a freestanding top-tilde character, ˜, distinct from the normal one, ~, and distinct from precomposed characters like ñ and ã? Is it meant for use as a combining character? That article has a chart of combining characters, but its combining tilde, ̃, is distinct from the one that I've used in the section header. ˜˜˜˜

I didn't expect it to work for a signature, but why not run a test :-) Nyttend (talk) 12:29, 12 November 2016 (UTC)

Is the question what was the Unicode people's rationale for having a separate non-combining overtilde? Ascii has just one tilde character. It'd make sense if in the original Ascii the tilde was an overtilde so one could do tricks like ñ = n backspace ~ blank blank on teletypes and daisy-wheel printers.With the advent of video terminals (and later micros with a video and keyboard circuitry built-in) this became unnecessary and the original tilde sank down to the centerline. But the overtilde still occurs in printed documents (program listings etc) as a free-standing character. In other words, the overtilde became "a thing." Perhaps they added it because someone somewhere said they still needed it. Asmrulz (talk) 16:35, 12 November 2016 (UTC)

Yes, that was the question. It sounds like your answer is "no clue, but it's in use, so they can't trash it now". If that's what you mean, thank you; "no idea" is always reasonable, since by definition it's the best you can do :-) Nyttend (talk) 23:02, 12 November 2016 (UTC)

It's a compatibility character, i.e., "a character that would not have been encoded except for compatibility and round-trip convertibility with other standards." Older encodings like Windows-1252 and Mac OS Roman included it as an overstrike modifier. I don't know whether anyone still needs it, but it doesn't matter. Unicode even includes characters that no one has ever used, such as the ghost kanji, just because an earlier standard had them. -- BenRG (talk) 04:24, 13 November 2016 (UTC)