Can I make a PDF that allows people to easily add and remove tally marks to a form text field?

[SadieBlue]

Can I make a PDF that allows people to easily add and remove tally-marks to a form text field?

Bellow is what I have.... the user can type words or symbols in the highlighted box below each letter but I'd like to make it so any letter typed makes a tally mark. Or clicking in the box will add a tally-mark and clicking on it again will remove it.

Each box can have up to 3 tally marks. (PS it doesn't have to be a tally mark it could be multiple check marks or something similar)

[Thom Parker]

If by tally mark you mean a custom graphic, then it gets very complicated. 

The easiest approach is to use the "Line" markup annotation. The script will need to add this annoation as Read Only so the user can't move it around. 

You'll need good programming skills to pull this off. 
Here's an article on coordinates in PDF and how to place annotations.

https://www.pdfscripting.com/public/PDF-Page-Coordinates.cfm?sd=40