poklane on 08 September 2016
Atletico Madrid and Real Madrid both have been handed a transfer ban that prevents them from registering any players at national and international level for the next two complete and consecutive registration periods (transfer windows) after their appeals have failed.
http://www.fifa.com/about-fifa/news/y=2016/m=9/news=fifa-rejects-appeals-of-atletico-de-madrid-and-real-madrid-in-relation-2831432.html?
This means that both clubs can't register any new players until January 1st 2018. They can still buy players in the meantime, but those players simply won't be eligible to play for the team because they can't get registered.
Edit: Real Madrid will appeal at the CAS http://www.realmadrid.com/en/news/2016/09/official-announcement
