Secret codes hidden in the Call of Duty: WWII Steam Key PC EU Resistance DLC trailer were unveiled, rewarding players with free CoD: Resistance WWII funds, a business card and more.

Like many Call of Duty trailers, there was some hidden news in the trailer for the first DLC "Resistance" pack, and Eagle-Eyed fans have now discovered the hidden codes.

The DLC Resistance package has launched three new multiplayer maps: Anthropoid, Valkyrie and Occupation, and the live action trailer uses hidden messages to make subtle references to those places.

While the DLC package is paid or is free to seasonal pass holders, the codes identified through a comprehensive trailer review provide free content when they are entered into the appropriate Call of Duty website.

Simply enter the three codes (CWBYE, NSUWC and ZZPJX) on the Call of Duty WWI website to get the free content. The resistance card will be awarded once it is in play in the game, but you must make sure that you are connected to the Call of Duty page.