Short question: The examples, documentation and some comments on the forum indicates that RFCs can be sent and implemented with or without a custom ID.
In one post I think Aaron wrote something along the lines of "You don't have to specify an ID, but you can do that if you want to optimise bandwidth".
So, when would you specify an ID and what effects does it have? From a coding POV, skipping IDs are certainly easier as you don't have to keep track of which you have used. So any clarification would be very helpful.
Thanks!