+The \fBkeyname\fR routine returns a character string corresponding to the key \fIc\fR.
+Control characters are displayed in the \fB^\fR\fIX\fR notation.
+Values above 128 are either meta characters, shown in the \fBM-\fR\fIX\fR notation,
+or the names of function keys, or null.
+The corresponding \fBkey_name\fR returns a character string corresponding
+to the wide-character value \fIw\fR.
+The two functions do not return the same set of strings;
+the latter returns null where the former would display a meta character.