One is called

vaticinium ex eventu, prophecy from an event,

meaning: an event is happening, and the prophecy (which in fact should be always before the event) is adapted.

This is exactly what takes place right now with the pope. He is resigning, and boom - many find it predicted by Nostradamus or the papal prophecies. In fact the event took first place and then came the adaption of a prophecy.

This is no honest research and working but a kind of deception: you always correct a prophecy after an event has taken place.

A real prophecy has a clear algorithm:

prophecy - fulfillment - event takes place,

while there is no correction and adaption after the event is allowed.

Actually this follows a second fallacy called

circulus vitiosus or vicious circle; that means, you take already for granted in your equation for what you are looking for; it is like a judge researching who did the crime, and he is assuming right from the beginning a certain suspect did it without really knowing; a vicious circle is no open searching, but confirmation of what you have always known.