CLCS

Tilde X: Hexadecimal

This is just like ~D but prints in hexadecimal radix (radix 16) instead of decimal. The full form is therefore ~mincol,padchar,commachar,comma-intervalX.

~X binds *print-escape* to false, *print-radix* to false, *print-base* to 16,

and *print-readably* to false.