These exit routines contain instructions to be executed when asynchronous RPL-based operations are completed. In any individual conversation-establishment, communication, or other RPL-based macroinstruction, if an RPL exit-routine address is specified, the exit routine is scheduled as an alternative to VTAM's posting an event control block (ECB) when the requested action completes. Using the ECB provides programs with greater control over the order in which events are to be handled. A program can use a mixture of ECB-posting and RPL exit routines, or it can use all one or the other.