* lisp/emacs-lisp/cl-seq.el (cl-reduce): Explain what happens when
using :from-end (bug#57273).
If SEQ contains exactly one element and no :INITIAL-VALUE is
specified, then return that element and FUNCTION is not called.
+If :FROM-END is non-nil, the reduction occurs from the back of
+the SEQ moving forward, and the order of arguments to the
+FUNCTION is also reversed.
+
\n(fn FUNCTION SEQ [KEYWORD VALUE]...)"
(cl--parsing-keywords (:from-end (:start 0) :end :initial-value :key) ()
(or (listp cl-seq) (setq cl-seq (append cl-seq nil)))