只是将它们标准化。在四种归一化方案中的任何一种下,U+F9D1 变为 U+516D:
$ export PERL_UNICODE=S
$ perl -le 'print "\x{F9D1}\x{516D}"' | uniquote -v
\N{CJK COMPATIBILITY IDEOGRAPH-F9D1}\N{CJK UNIFIED IDEOGRAPH-516D}
$ perl -le 'print "\x{F9D1}\x{516D}"' | nfd | uniquote -v
\N{CJK UNIFIED IDEOGRAPH-516D}\N{CJK UNIFIED IDEOGRAPH-516D}
$ perl -le 'print "\x{F9D1}\x{516D}"' | nfc | uniquote -v
\N{CJK UNIFIED IDEOGRAPH-516D}\N{CJK UNIFIED IDEOGRAPH-516D}
$ perl -le 'print "\x{F9D1}\x{516D}"' | nfkd | uniquote -v
\N{CJK UNIFIED IDEOGRAPH-516D}\N{CJK UNIFIED IDEOGRAPH-516D}
$ perl -le 'print "\x{F9D1}\x{516D}"' | nfkc | uniquote -v
\N{CJK UNIFIED IDEOGRAPH-516D}\N{CJK UNIFIED IDEOGRAPH-516D}
此处提供了许多基本的 Unicode 工具,包括那些工具。