Introductory it as Object
The following fairly fixed phrases also have introductory it as Object.
I had it in mind to write a book about how much one should strive for perfection.
Officials let it be known that they were hoping to get more than two thirds of the members together.
I wouldn't put it past your father to insist that this behaviour is kept secret from you.
The institutions simply took it for granted that the debtor countries should honour their debts in full.
We grabbed sleep when we could and took it in turns to keep watch.
In the phrase see to it that, the prepositional phrase to it is the prepositional Object.
They stopped the concert, shouted for a doctor, and saw to it that the player was given medical attention.