[fomine3]

Maybe the guess order depends on locale reasonably. GP is my experience mainly on old days ja-JP localed Windows software. IIRC Unix software tend to not good at guess so maybe you referring them.

Nowadays I rarely see new EUC-JP contents (or I just not recognized) but still sometimes I encounter mojibake on Chrome while visiting old homepage (like once per month). For web page, anyway most modern pages (including SJIS) don't rely on guess but have <meta charset> tag so mojibake very rarely happen. For plaintext files, I still see UTF-8 file shown as SJIS on Windows Chrome.

Viewing Japanese only UTF-8 text is totally fine for Japanese localed Windows/Mac/(Linux but YMMV). So your case is to view the text on non-Japanese locale. It possibly have a problem but how SJIS solved the issue? What software switches font if it opens SJIS file? Is the app/format don't support specifying font/lang like HTML/Word?

I believe no developer want to treat foreign charset like GBK/Big-5/whatever. There are very few information. If developer can switch reading charset on a file, then they can also switch font.

[lmm]

> Viewing Japanese only UTF-8 text is totally fine for Japanese localed Windows/Mac/(Linux but YMMV). So your case is to view the text on non-Japanese locale.

The issue is that realistically a certain proportion of customers are going to have the wrong locale setting or wrong default font set.

> It possibly have a problem but how SJIS solved the issue? What software switches font if it opens SJIS file? Is the app/format don't support specifying font/lang like HTML/Word?

Certainly Firefox will use a Japanese font by default for SJIS whereas it will use a generic (i.e. Chinese) font by default for UTF-8. I would expect most encoding-aware programs would do the same?

> If developer can switch reading charset on a file, then they can also switch font.

Sure, but it works both ways. And it's actually much easier for a lazy developer to ignore the font case because it's essentially only an issue for Japan. Whereas if you make a completely encoding-unaware program it will cause issues in much of Europe and all of Asia (well, it did pre-UTF8 anyway).