?
Extra-role behavior is defined as behavior which benefits the organization and/or is intended to benefit the organization, which is discretionary and which goes beyond existing role expectations.
Van Dyne, L., Cummings, L. L., & Parks, J. M. . (1995). Extra-role behaviors: In pursuit of construct and definitional clarity (a bridge over muddied waters). Research in Organizational Behavior An Annual Series of Analytical Essays and Critical Reviews Vol 17 1995, 17(1), 215–285.