Some wrecks, those considered the higher quality ones, can only be looted once per character.
The timing of the maintenance re-starts tends to vary, so as players do not know when it will happen.
That saves on camping ...
Hoodlum
Some say he is a proud member of: "The most paranoid group of people in the Community."
Codename weapons are horribly outdated. That's the point now. These weapons were uber a decade ago, but now Faction weapons have gotten buffed so that you don't need codes anymore.
And yet you can still find people buying them for tens of millions...
Some wrecks can be looted as many times as you want on one character. Some cant.
Also, the hull on a wreck will regenerate. Sometimes it helps to view the wireframe of the wreck to find out if it has been looted or not. Note that if its in an area where there is radiation damage, then chances are that the wireframe will tell you its taken damage already.
EDIT: Also, its its "one time per NAME". I know, I remade a character with the same name and tried looting a fresh wreck, and it didn't work. Incidentally, you could...nah you can figure that out on your own.
While being quite funny, your sig was the biggest one i've ever seen so far. No more than 700x250 please. ~utrack http://pastebin.com/SYQXBufs
You can only get codes from wrecks which have not been looted before. The wrecks will have been harvested by someone else, but after it's been looted once, it can't be again till next server restart.
I still think that codenames are... not Uber but worth spending 20m each on them (that price is exaggerated). I love codes, and buying and harvesting them is fun, thrilling and adds more awesomeness to disco. Hope more codes will be added in in future.