There is a topic in Alternative History or time travel that claims there has been revisions in the current reality. One of the examples is in the spelling of the Bernstein Bears series name. Some people remember the spelling one way, others another. Some remember the painting of King Henry VIII holding a turkey leg, others not. Some remember the arrival of the Titanic in NYC, others that it sank. What is the name of this effect? There's a term for it. And is there a wikipedia entry for it?