777

Because System 7 had taken its name from Apple's operating system at the time, there was a legal discussion resulting in System 7 being forced to use a pseudonym in the US. They chose 777 which led to a confusing combination of album releases: first 'System 7' by System 7 which was reissued as '777' by 777 in America and then a second UK album '777' by System 7.

Data provided by Discogs