Need to understand DUPS_OK_ACKNOWLEDGE Mode


I need to understand in which case we have to use DUPS_OK_ACKNOWLEDGE mode. Really helpful if i get realtime example for all the acknowledgement modes.

I am getting the below error in server logs while subscribing the message from Queue.

I am subscribing message from UM. Connection type is NO_TRANSACTION.

I have attached trigger properties with this.

Kindly help me to understand this topic.