OPEN and CLOSE macroinstructions are always associated with the issuing task. RPL-based macroinstructions issued in TCB mode are usually associated with the issuing task; however, for communication macroinstructions, VTAM® does most of its processing under the session task and so switches the task association to that task. (For RECEIVE OPTCD=ANY, intermediate processing is also done under the ACB task, which thereby becomes the associated task for a certain period of time.)