From Wikipedia:
The Paul McCartney Archive Collection is an ongoing project to remaster and reissue Paul McCartney’s solo catalogue, including various albums released with Wings. These editions feature deluxe packaging and bonus rare tracks. Thus far, there have been fourteen releases since the project began in 2010 (seven solo albums, six Wings albums, and one new Wings live album of previously unreleased material). They are overseen by McCartney himself and remastered at Abbey Road Studios. Albums reissued in this project are visually marked by a white stripe along the left side of the album cover that reads “Paul McCartney Archive Collection” and a copy of McCartney’s signature.
The albums are typically released in a variety of formats: a “standard” edition that contains the original album digitally remastered on one CD; a “special” edition which contains additional discs of bonus tracks; and a “deluxe” edition which comes with extra features like bonus CDs or DVDs of unreleased material packaged in a hard-bound book. Some releases contain booklets, rare photos, interviews, artwork, promotional video clips, or documentaries. The “special” editions of the albums were also released as double LPs on 180 gram “audiophile vinyl”, with the original album on one record and bonus material on the second. The records also came with a download card for MP3 versions of all tracks included. The special editions of the albums are available on streaming services worldwide.
The project has also inspired a fan-driven project, called the “Ultimate Archive Collection“, which has collected a greater number of McCartney and Wings albums, including bootlegs and unofficial albums. This was created as a response to the dissatisfaction among some fans at the slow rate of releases, as well as the perceived low number of bonus tracks included with each album.