Quite often there comes a point where a flag note needs to be created. The kind of note that needs either a triangle or swuare or what ever around the note number.
Currently there is no easy/parametric method for doing this. Similar to how you are able to box in a dimension with the basic command, functionality should be built into the text editor within the drawing environment allowing users to place a certain polygon around text.
Please see the attached thread.
http://forums.autodesk.com/t5/Inventor-General/Add-a-box-around-a-note-number/m-p/4646953#M489860