To get the RPC command for “show version”, pipe output to “| display xml rpc”
lab@aristotle-re0> show version | display xml rpc
<rpc-reply xmlns:junos="http://xml.juniper.net/junos/12.3R2/junos">
<rpc>
<get-software-information>
</get-software-information>
</rpc>
<cli>
<banner></banner>
</cli>
</rpc-reply>
This yields “get-software-information”. Easy!