Forfarian is correct. To show seriousness about the process, the bride-to-be and the groom-to-be 'consigned pledges' when they gave in their names for proclamation. This could either be done by paying a sum of money themselves or by naming a third person who would stand surety for the amount. The usual word for this person is 'cautioner', but 'bail' means the same. Here the pledges are called 'bonds'.
If the marriage went ahead within forty days and there was no scandal attached to it, the money was returned or the cautioner/bail released from their obligation. If the marriage did not take place, ran past the forty days, or was accompanied by some scandal, the money was forfeit. If a cautioner had stood surety or bail for the bond (the undertaking to marry in a timely and scandal-free manner) they would have to hand over the money at that point.
