Application Messaging is used by PeopleSoft applications to communicate with one another. This is true not just for 8.1x and 8.4 applications, but also between an 8.1x and an 8.4 application. For example, the HRMS 8.3 applications, which are based on PeopleTools 8.15, can communicate with Financials 8.4applications, which are based on PeopleTools 8.4, using Application Messaging. If specific issues materialize relating to the Application Messages published by certain applications, these new messages will be made available to customers.