In case it helps anyone else one day: I found this helpful - the English isn't perfect (too many commas!) but otherwise seems fairly lucid:
"Second, in the contract, payment is made dependent on the
deletion of existing encumbrances.
"– If the creditor is a bank, the bank normally sends alls documents necessary for
cancelling the mortgage from the register to the notary and advises the notary to
make use of these documents only, if the bank receives a certain amount of money (that is the bank’s claim
still secured by the mortgage).
"[...]
"– Afterwards, the bank tells the notary, that it has received the money and that now he may
use the documents to cancel the bank’s mortgage."
http://www.eui.eu/Documents/DepartmentsCentre...