What year did MLS introduce the Designated Player rule?

The DP rule, often called the Beckham Rule, was created specifically to allow MLS to sign the English superstar, whose salary would have been impossible under the existing salary cap.

Since 2007, the DP rule has brought dozens of world-class players to MLS, including Thierry Henry, David Villa, Carlos Vela, and Lionel Messi. It fundamentally changed the league's talent level and global profile.