问题
I was surprised to find that no Unicode normalization of the Ł character maps it to something like L + combining stroke. That was my best explanation to understand why Ł to get mapped to L rather than ? when converting from a Unicode-capable encoding to ASCII or a code page that doesn't have the Ł character. How does it work otherwise? Does the standard define fallback characters?
来源：https://stackoverflow.com/questions/58674948/how-does-unicode-conversion-to-ascii-know-to-map-%c5%81-to-l