this is like attivo and passivo in the sense of assets and liabilities or income and expense.
The guarantee is attivo when it is received, like an asset, you can only benefit from it
While the passivo is a guarantee you have granted (a bank will earn a commission on a guarantee it grants, it is a potential liability, you can lose.
Italian accountants talk about off-balance sheet items as attivo an passivo in the same way as on-balance sheet items.