Neither are high and low surrogates - those are big ranges of code points that are illegal except for one specific (and not recommended) encoding (utf-16). Yet,

Neither are high and low surrogates - those are big ranges of code points that are illegal except for one specific (and not recommended) encoding (utf-16). Yet, there they will remain in Unicode. Digits definitely are a form of text though. Unicode is for writing systems, which definitely includes writing numbers