[pro] Reader macro definition in CLHS

------------------- reader macro n. 1. a textual notation introduced by dispatch on one or two characters that defines special-purpose syntax for use by the Lisp reader, and that is implemented by a reader macro function. See Section 2.2 (Reader Algorithm). 2. the character or characters that introduce a reader macro[1]; that is, a macro character or the conceptual pairing of a dispatching macro character and the character that follows it. (A reader macro is not a kind of macro.) -------------------

I do not understand item 1. In code

... (set-macro-character #\G (lambda(s c) 9.81)) (setf s (* (/ G 2) (* tt tt)))

#\G is the reader-macro in a sense 2. What is the reader-macro in a sense 1.?

Kazimir Majorinc