I'm thinking it might be something like a box you check on your witholding, and fill in an amount you are willing to commit to for the year.
After a couple of weeks you wouldn't even notice the extra 5 dollars or whatever amount.
I think it's fairly common to find boxes on state tax returns that contribute a dollar toward wildlife and parks.
Tax , is probably a poor choice of words.
Voluntary contribution -- that might be a better choice in words.
It could be an annual thing where you check the box and fill in a blank to how much of your taxes you wish to apply to education. Actually, we have the ability today for each of us to pick and choose where our taxes should go -- built in excuse for failed projects - "the people didn't contribute enough for that program so we had to drop it."
Or it could be another payroll withholding - sent in by your employer on the quarterly basis -- more work, but not any different then withholding your share of your health insurance premium and sending it to the insurer.
We might be on to some thing here.