The working title was "Project X.

“Project X” sounds like a placeholder, because that’s exactly what it was.

Pink Floyd started recording Wish You Were Here under that name—along with “The Black Album” (a nod to the black sleeve). They didn’t settle on the final title until late in the process.

Not the most exciting trivia, but it’s the truth. Bands call albums “Project [Letter]” all the time when they’re still figuring out the concept.