Guile Reference Manual
Comments in Scheme source files are written by starting them with a
semicolon character (
;). The comment then reaches up to the end
of the line. Comments can begin at any column, and the may be inserted
on the same line as Scheme code.
;; Comment too
(define x 1) ; Comment after expression
(let ((y 1))
;; Display something.
;;; Comment at left margin.
(display (+ y 1)))
It is common to use a single semicolon for comments following
expressions on a line, to use two semicolons for comments which are
indented like code, and three semicolons for comments which start at
column 0, even if they are inside an indented code block. This
convention is used when indenting code in Emacs' Scheme mode.