Continental lock
A Continental lock is when you own ALL the facilities on the continent. When you first get a lock, all towers will revert to that Empire's control.
A continental lock prevents enemy troops from using the HART drop pods to reach that planet, forcing them to use warpgates. In addition, friendly troops may use the /broadcast channel to talk to any friendly on the continent.
A lock will also provide Empire Benefits, depending on the continent.
Also refered to as a Continent Lock, or Cont lock.