-If a character in \fIwstr\fP is a tab, newline, carriage return or
-backspace, the cursor is moved appropriately within the window.
-A newline also does a \fBclrtoeol\fP before moving.
-Tabs are considered to be at every eighth column.
-If a character in \fIwstr\fP is another control character,
-it is drawn in the \fB^\fIX\fR notation.
-Calling \fBwin_wch\fP after adding a control character
-(and moving to it, if necessary)
-does not return the control character,
-but instead returns a character in the ^-representation
-of the control character.
+X/Open Curses does not specify any error conditions.
+In
+.IR \%ncurses ","
+they return
+.B ERR
+if
+.bP
+.I win
+is
+.BR NULL ","
+.bP
+.I wstr
+is
+.BR NULL ","
+or
+.bP
+an internal \fB\%wins_wch\fP(3X) call returns
+.BR ERR "."
+.PP
+Functions prefixed with \*(``mv\*('' first perform cursor movement and
+fail if the position
+.RI ( y ,
+.IR x )
+is outside the window boundaries.