Access is a character from the DC/Marvel crossover series. During the construction of the Amalgam Universe (during which Batman merged with Marvel's Wolverine to become Dark Claw) Axel Asher hid fragments of the DC universe within Batman (such as he hid fragments within Marvel within Captain America, whom Batman fought in Avengers v. Justice League).
Batman and Captain America teamed up to aid Access in restoring the Universe's continuity. As a result, neither should remember the instance.
Access is the person responsible for fixing the continuity whenever there is a crossover between the universes, a precursor to the reformation of Amalgam, such as when Batman teamed up with Spider-Man to battle the Kingpin and Ra's al Ghul.
The Joker is a notable exception to this as he seems to remember these past team-ups, possibly as a result of his hyper-awareness or super-sanity.