CLCS

Tilde O: Octal

This is just like ~D but prints in octal radix (radix 8) instead of decimal. The full form is therefore ~mincol,padchar,commachar,comma-intervalO.

~O binds *print-escape* to false, *print-radix* to false, *print-base* to 8,

and *print-readably* to false.