Foreign Non-Deposit Int/Annuit/Royalt/Divs Eform 12

I am filing out eform 12. I have a tiny amount 20e dividend(gross) from a company on the dutch stock exchange.

I read that I have to declare under section Foreign Non-Deposit Int/Annuit/Royalt/Divs

I entered 20e into the gross amount field

There is a non mandatory field called Non refundable foreign tax deducted.

Do i need to enter a value here?

There was no field like this when i entered my US and Irish dividends

I think i paid 15% tax when i got the dividend through the broker.

is it also true i need to enter US dividends under this section?. i read this in an article.I thought it was strange considering there is a specific section on eform 12 for US dividends.