In Engineering toolset, look for the "SNMP Trap editor", then load the forwardsyslog.trap file from your main Orion directory. You will then be able to change the order of the information contained in the trap, and add new items (with variables). If you are sending traps to another system, you might want to edit (manually) the MIB file, so they are able to interpret the information you are sending.
Hope this helps!