Here is the list of reader options generated by typing
(read-options 'full) in Guile. You can also see the default
keywords #f Style of keyword recognition: #f, 'prefix or 'postfix case-insensitive no Convert symbols to lower case. positions yes Record positions of source code expressions. copy no Copy source code expressions.
Notice that while Standard Scheme is case insensitive, to ease translation of other Lisp dialects, notably Emacs Lisp, into Guile, Guile is case-sensitive by default.
To make Guile case insensitive, you can type