(Integer Basics): Document CL style read syntax for

integers in bases other than 10.

lispref/numbers.texi

@@ -67,6 +67,18 @@ initial sign and optional final period.
 -0               ; @r{The integer 0.}
 @end example
 
+@cindex integers in specific radix
+@cindex radix for reading an integer
+@cindex base for reading an integer
+  In addition, the Lisp reader recognizes a syntax for integers in
+bases other than 10: @samp{#B@var{integer}} reads @var{integer} in
+binary (radix 2), @samp{#O@var{integer}} reads @var{integer} in octal
+(radix 8), @samp{#X@var{integer}} reads @var{integer} in hexadecimal
+(radix 16), and @samp{#@var{radix}r@var{integer}} reads @var{integer}
+in radix @var{radix} (where @var{radix} is between 2 and 36,
+inclusivley).  Case is not significant for the letter after @samp{#}
+(@samp{B}, @samp{O}, etc.) that denotes the radix.
+
   To understand how various functions work on integers, especially the
 bitwise operators (@pxref{Bitwise Operations}), it is often helpful to
 view the numbers in their binary form.