ANSI Common Lisp   2 Syntax   2.4 Standard Macro Characters   2.4.8 Sharpsign

2.4.8.8 Sharpsign O

#Orational reads rational in octal (radix 8). For example,

 #o37/15 ==31/13
 #o777 ==511
 #o105 ==69 ;1058

The consequences are undefined if the token immediately following the #O does not have the syntax of an octal (i.e., radix 8) rational.