-.SH RETURN VALUES
-Upon successful completion, these functions return OK.
-Otherwise, they return ERR.
+.SH RETURN VALUE
+Upon successful completion, these functions return \fBOK\fP.
+Otherwise, they return \fBERR\fP.
+.PP
+Functions with a "mv" prefix first perform a cursor movement using
+\fBwmove\fP, and return an error if the position is outside the window,
+or if the window pointer is null.