The $LINKAGE_PAIR and $CALL macros maintain an assembly-time
    list of linkage pairs that the $LINKAGE_PAIR macro has stored in
    the linkage section. This list enables $LINKAGE_PAIR and $CALL
    to use the same linkage pair for multiple routine calls to the
    same routine. You can clear this list of linkage pairs with the
    $RESET_LP_LIST macro.

    Under normal circumstances, you do not need to clear the linkage-
    pair list. Some of the times when you do are as follows:

    o  When you change the psect assigned to the linkage section.

    o  If distance from the linkage section of your current routine
       falls more than 32K bytes beyond where the linkage pair has
       been stored.