What BBC charity event featured the 2013 mini-episode 'The Office Revisited'?

The BBC charity event featuring the 2013 mini-episode “The Office Revisited” was Comic Relief. The short, also known as “The Return of Brent,” brought Ricky Gervais back as David Brent for a fundraising broadcast.

Comic Relief is a British charity founded in 1985 by comedian Lenny Henry, writer Richard Curtis and others. Its major fundraising campaigns traditionally alternate between celebrity comedy, entertainment and appeals about poverty and humanitarian causes. The event’s best-known public campaign is Red Nose Day, but Comic Relief is the charity behind it; they are not interchangeable answers in this question.

“The Office Revisited” returned to the world of Wernham Hogg and David Brent after the original series and Christmas specials. It was a charity short rather than a regular episode of the BBC sitcom. The title is also easy to confuse with the 2016 film “David Brent: Life on the Road,” which was a separate commercial project and not the 2013 fundraiser.