Packet reading

[Parallax]

So I'd like to keep the other thread on track while I put this one in the right place. Here we were talking about packet reading and extraction. I've got a couple packets, and I wanted to know if I'm reading them right.

I was testing out syncing packets:
Mara C? X:169 Y:5 Z:24
Target: 02 04 01 00 35 01 06 81 51 00 00 00 00
Sync: 02 04 01 00 39 01 08 80 c8 ea 01 30 39 08 00

Zia X:771 Y:7 Z:-442
Target: 02 04 01 00 a1 01 06 81 51 00 00 00 00
Sync: 02 04 01 00 a6 01 08 80 c8 95 05 b0 0f 08 00

The red seems to be a packet header, followed by a counter. I hadn't played enough to see how many bits were used for counting (have it roll up into the next bit).

The green in the target packet is the same no matter what I'm targeting. Perhaps a target switch?

Finally, The bold bits only seem to change depending on what is double clicked, one door's will be slightly different to the one beside it. I can't decide whether it's coordinates or an item code/id because there doesn't seem to be any math to it.

I know they probably don't matter because they're client-side reality packets, I just wanted to see if I understood the syntax. Am I way off?