In 17.7.1 the proposal states: "All collective communication operations initiated before the call to MPI_COMM_VALIDATE must also complete before it is called, and no collective calls may be initiated until it has completed." Considering the case where FailHandlers are used in the 'ALL' operating mode. In this mode, a user may want to call validate in all of the FailHanlders to synchronize them. But if the FailHandler was triggered out of a collective operation over a communicator that does -not- include the failed process then the user cannot write a correct program (since they cannot cancel, and may not be able to complete the collective operation). My suggestion is that we remove this sentence. Do folks have a problem with this? Thanks, Josh -- Joshua Hursey Postdoctoral Research Associate Oak Ridge National Laboratory http://users.nccs.gov/~jjhursey