Clans are a group of people on Warzone that were introduced in update 2.2. Quote from the blog: "Warzone now has an official built-in clan system! This allows players to form clans, which puts an icon next to each clan member’s name and gives clans ways to communicate easier.
Each clan gets a clan page, which works somewhat like a player’s profile page. They can upload their own image and enter the details they’d like to present. You can view all clans on the new Community -> Clans tab.
When you create your own clan, you have full control over who is allowed in your clan. There’s no limit to the size of clans, and you can remove anyone at any time."