What does this do?

Alright, so I was playing on a server, there was a restart, came back, and I got the Account Still Restricted error when I attempted to log in. This kept up for about 45 minutes. I tried logging in with opening the updater first, as well as just opening up from the Game.exe. well, after a while of this, i just started screwing with it (I was kind of in a bored don't have anything else to do mood) and I had the Packet Editor out. I tried logging in, and I took the send code and tried putting that in to see what would happen, nothing. Well, not too much later, a random code input went through "send>> 03 00". I didn't do anything to my knowledge. And, then, I was still waiting with the game open, and this code went through again. So, i retyped the code and pressed "send" and then I did it again, and then the game said "connection with server, disconnected". Well, I went back on, and tried logging in again, BAM, no Account still restricted, just went straight through. So, yeah, just out of curiosity, anyone wanna tell me what that code was, or if it was just a random coincydink?

03 00 is just the "keep alive" code. It sends on a timer to the server to let the server know that you're still connected even though you're not sending packets, aka doing any actions.

Ok, that make sense, then why does it log me out, when i send that code twice?

The reason you sometimes get disconnected when sending packets is because certain packets either do not exist or like the "03 00" do not give a specific action that can be sent, so when you send packets like the login one, choosing a character, creating a character, packets like those cannot be sent so you will get disconnected- well thats my idea of why you got disconnected when sending "03 00"