Better view of the certificate
The Corps of Cadets was a Starfleet Academy group for which Jean-Luc Picard was a member of in 2323. This group was mentioned on the Starfleet Academy marathon certificate. (Star Trek Nemesis)
Along with the rest of the family album, this certificate was initially created for Star Trek Generations, though it was not seen in that movie. A behind-the-scenes feature in the July 2002 issue of Star Trek: The Magazine (Volume 3, Issue 03, Page 70) offered the better view depicted here.
In 2372, per orders from Starfleet Command, the entire Corps of Cadets was assigned to field duty. (DS9: "Paradise Lost")