In particular, UTF-16 surrogates use 2048 code points in the basic multilingual plane (BMP), but surrogates allow another 2^20 code points to be encodable in ad

In particular, UTF-16 surrogates use 2048 code points in the basic multilingual plane (BMP), but surrogates allow another 2^20 code points to be encodable in addition to the non-surrogate 65536−2048 code points of the BMP.