Free-floating projection view complete with an arrow set ("View indicator") and letters to help find the view at its remote location.
1. Create a Projection View (Auxiliary probably works too, didn't try it)
and Add Arrows.
2. Erase the view (not delete the view), but keep the arrows (there's a command line prompt that asks about this).
3. Now create the view again, either as a General view (manually oriented)
or as a Projection (which you can then "unhook" from its parent using View;
Modify View; Modify Type to General). Either way you can put this second
view anywhere you want and reorient it freely if desired.
4. Modify; (Value) and change the text string that labels the arrow set to
the letter you want. Fortunately, ProE will keep track of this with the
other Detail/Section letters.
5. Put a matching label (text string) under the view at its remote location.