( 4 ) The following modes shall be available for using the ICM : ( a ) Application-to-application mode ( A2A ) In A2A , information and messages are transferred between the PM and the participant 's internal application .
( 4 ) The following modes shall be available for using the ICM : ( a ) Application-to-application mode ( A2A ) In A2A , information and messages are transferred between the PM and the participant 's internal application .