Mike Ash (comments): Thus we can see that the structure of the tagged pointer strings is: If the length is between 0 and 7, store the string as raw eight-bit characters. If the length is 8 or 9, store the string in a six-bit encoding, using the alphabet “eilotrm.apdnsIc ufkMShjTRxgC4013bDNvwyUL2O856P-B79AFKEWV_zGJ/HYX”. If the length is 10 … Continue reading NSTaggedPointerString