-The function \fBnew_menu\fR returns \fBNULL\fR on error.
-
-The function \fBfree_menu\fR returns one of the following:
+The function \fBnew_menu\fP returns \fBNULL\fP on error.
+It sets \fBerrno\fP according to the function's failure:
+.TP 5
+.B E_NOT_CONNECTED
+No items are connected to the menu.
+.TP 5
+.B E_SYSTEM_ERROR
+System error occurred, e.g., malloc failure.
+.PP
+The function \fBfree_menu\fP returns one of the following: