Major Section: PROGRAMMING
(Upper-case-p x) is true if and only if x is an upper case
character, i.e., a member of the list #A, #B, ..., #Z.
The guard for upper-case-p requires its argument to be a standard
character (see standard-char-p).
Upper-case-p is a Common Lisp function. See any Common Lisp
documentation for more information.