The U.S. Court of Appeals for the Fifth Circuit has partially upheld a National Labor Relations Board ruling that workplace rules by cellphone carriers T-Mobile and MetroPCS banning photography or recording on corporate premises illegally restricts its employees from exercising their right to unionize.

The NLRB brought a complaint against the affiliated cellphone companies in 2014 after the Communication Workers of America alleged that four provisions in its corporate employee handbooks violated the National Labor Relations Act.

The NLRB later determined those four provisions, including a workplace conduct policy, a commitment-to-integrity policy, a recording policy and reasonable accepted use policy, all discouraged workers from unionizing. T-Mobile and MetroPCS appealed those decisions to the Fifth Circuit.

In its July 25 decision in T-Mobile v. National Labor Relations Board, the Fifth Circuit declined to enforce three of the NLRB's findings, including that the company workplace conduct policy, which encouraged employees to maintain a "positive work environment," discouraged discussions of unionizing; that the commitment-to-integrity policy, which prohibits "arguing or fighting," would inhibit the robust discussion of labor issues; and that the acceptable use policy, which ban employees from sharing nonpublic company information by email, prohibited sharing wage information.

But the appellate court upheld the NLRB's finding that a recording policy that bans employees from "any and all photography on corporate premises without permission from a supervisor" would discourage employees from engaging in a protected activity.

"This ban is, but its own term alone, stated so broadly that a reasonable employee, generally aware of employee rights, would interpret it to discourage protected activity, such as even an off-duty employee photographing a wage schedule posted on a corporate bulletin board," wrote Judge E. Grady Jolly.

"Because a reasonable employee would construe the recording policy to prohibit forms of protected activity, we hold that the Board's determination that the recording policy violated the NLRA is supported be a reasonable interpretation of the record. Its order will be enforced in that respect," Jolly wrote.