T-Mobile’s employee handbook said: “Employees are expected to maintain a positive work environment by communicating in a manner that is conducive to effective working relationships with internal and external customers, clients, co-workers, and management.” In 2016 the National Labor Relations Board ruled the rule unlawful. Labor disputes, the Board said, involve “arguments, and less-than-‘positive’ statements about terms and conditions of employment.”
On July 25, 2017, the Fifth Circuit Court of Appeals disagreed. It found that “a reasonable employee” would read the rule as “requiring professional manners.” The court said the rule expressed “a universally accepted guide for conduct.”