While shopping at Walmart, what do you do if you heard a serious voice announce over the intercom there’s a “Code Brown” happening in the store? Although a majority of Walmart’s “intercom codes” are used as “employee lingo” for basic day-to-day tasks, hearing a Code Brown means your life could be at risk.

As explained on the subreddit r/Walmart, “Code Brown” refers to an in-store act of violence and the procedures for the situation are based on what employees and staff command you to do. Walmart released a video detailing what to do in the event a store is targeted by a threat such as an active shooter.

The video instructs staff to be aware of their surroundings and keep doors locked to protect themselves and others inside rooms. Walmart also has codes for other critical events that may happen in-store, but fortunately, you’re more likely to hear codes related to harmless things like a spilled drink or additional customer service.