Meaning of high surrogate | Babel Free

Definitions

1. A code point in the range U+D800 through U+DBFF (the High Surrogates and High Private Use Surrogates blocks), used in UTF-16 to encode the high 10 bits of the 20-bit offset above U+FFFF of the code point belonging to a supplementary character.
2. A code point in the range U+D800 through U+DB7F (the High Surrogates block), excluding the range of code points used in encoding characters from the private-use planes 15 and 16.

CEFR level