When set at its default (ILPARAMS), you can specify a list of 0 or more arguments of the array element type instead of a single array argument, for any method that has an array as its last parameter. When NOILPARAMS is set, you can specify a list only when the target method specifies the PARAMS attribute.
$set ilparams *> you need this set if params is omitted class-id myClass. method-id main static. declare i as binary-long set i to self::Sum(1 2 3 4 5 6 7 8 9 10) display i end method. method-id Sum static. procedure division using by value params opds as binary-long occurs any returning ret as binary-long. set ret to 0 perform varying i as binary-long through opds add i to ret end-perform end method. end class.