HP 54710A User's Reference Manual page 367

Mask Menu
Edit Mask
Edit polygon
The Edit polygon softkey gives you access to a second level menu that
allows you to either edit or construct a polygon. Before entering this menu,
make sure that you have the correct polygon number selected with the
Polygon softkey.
Point Selects the point on the polygon you want to edit. You can use
the knob to scroll through the points on the polygon, or you can use the
keypad to jump to a point on the polygon. The point selector traverses
points that are previously defined.
The scope draws a dotted line from the first point to the last point. This
dotted line turns to a solid line when you exit the menu. Also, you cannot
cross lines as this turns one polygon into multiple polygons. For example, in
figure 23-6, A requires two polygons, while B is not a legal construction
because B requires lines to cross.
X Moves the cursor horizontally across the display allowing you to
define a point.
Y Moves the cursor vertically on the display allowing you to define a
point.
Insert Inserts a point at the location defined by the X and Y softkeys.
The point is inserted after the point number that the point softkey is set
to, and all remaining points are renumbered.
Delete Deletes the point selected by the point softkey.
Move Moves the selected point to the location defined by the X and Y
softkeys.
Delete polygon
Deletes the selected polygon.
Figure 23–2
23–10