Pete and all, Here is the input material for the replication discussion. The purpose of this document is to examine the feasibility of constructing a replication service on top of ACS. There are the two scenarios: Scenario 1: One-way synchronization, triggered by modification of the master ACS. Scenario 2: Two-way synchronization, triggered periodically. Conclusion: The replication service can work with ACS if it supports the update event notification as far as considering the two scenarios. My impression and proposal: The replicator is supported to be highly sophisticated especially in case of bi-directional synchronization. So I propose that ACS should provide infrastructural functionalities such as notification mechanism for the outer replication services instead of supporting replication capability by itself. This time I examined two scenarios to find out that the event mechanism is required to realize them. There may be more replication scenarios which have requirements for ACS spec. For example, the capability to get change histories of an AA should be useful. Your comments are very much welcomed. Sachiko