This functionality allows the user to erase the last mark made with the mark point element. It’s useful when the user has made a mark without intention or the place is incorrect. The button is placed on the right bottom of the window, it’s the fourth button, after the mark point button (Image 39).
![](http://sion.frm.utn.edu.ar/sonoUno/wp-content/uploads/2020/06/f39.png)
Another way to erase the last mark point is with the item delete last mark from the data display menu (Image 40), or with the shortcut key ‘Alt+Shift+D’ or ‘Option+Shift+D’.
![](http://sion.frm.utn.edu.ar/sonoUno/wp-content/uploads/2020/06/f40.png)