6.17.1.4 Case Sensitivity

Scheme as defined in R5RS is not case sensitive when reading symbols. Guile, on the contrary is case sensitive by default, so the identifiers

guile-whuzzy
Guile-Whuzzy

are the same in R5RS Scheme, but are different in Guile.

It is possible to turn off case sensitivity in Guile by setting the reader option case-insensitive. For more information on reader options, See section Reading Scheme Code.

(read-enable 'case-insensitive)

Note that this is seldom a problem, because Scheme programmers tend not to use uppercase letters in their identifiers anyway.