Are employees obligated to keep wages and salaries confidential?

Q. Can an employer prohibit employees from sharing confidential wage information with each other, such as rates of pay or the amount of wage increases?
A. The National Labor Relations Act (NLRA) protects employees for engaging in activity for “mutual aid and protection.” Sharing wage and wage increase information is considered protected information that assists employees in providing each other with mutual aid and protection.
Therefore, it is illegal under the NLRA to have, enforce or threaten to enforce such a policy. In other words, you can’t tell employees to keep their wages or salaries secret.