sentences:  However, they are not injective (they map different original glyphs and sequences to the same normalized sequence) and thus also not bijective (can't be restored).For example, the distinct Unicode strings "U+212B" (the angstrom sign "Å") and "U+00C5" (the Swedish letter "Å") are both expanded by NFD (or NFKD) into the sequence "U+0041 U+030A" (Latin letter "A" and combining ring above "°") which is then reduced by NFC (or NFKC) to "U+00C5" (the Swedish letter "Å").A single character (other than a Hangul syllable block) that will get replaced by another under normalization can be identified in the Unicode tables for having a non-empty compatibility field but lacking a compatibility tag.