I'm tired of seeing the words Troll, Bandwagon, White Knight, and "noob" thrown around like aerogel, with just as much impact since you guys don't have a loving clue what they mean.
Read or weep.
Let's go over the common case.
Newbie
The new guy, has the potential to become a handicap if influenced by the wrong people, and from there will likely migrate to Attention-Whore. Common Offenses include some minor handicap stuff, nothing serious, just newbie stuff.
Newbies are fragile, handle with care and love.
(Newbies are not noobies, noobs, n00bs, or other bastardizations. These are unprofessional insults, not classifications, don't use them or you will be shot)
Forum superstars
Forum regulars, long-time members, they've been through many historical forum events but contribute a bare minimum. The reason they're popular is simply because you see their names everywhere. Offenses include possible Attention-Whore behavior, possible Thread stuffting behavior, possible (rare) White Knight behavior, possible (very weak) Trolling behavior.
I fall into this category since people won't leave me the forget alone in IRC for instance. Allot of other regulars fall into this class as well.
Forum Elites
Beyond the superstars are these guys. They're generally intelligible and avid contributors as well as enthusiasts. They rarely commit offenses.
(note: Forum Elites will never call themselves as such or any other name promoting status, ever. If you think you're a forum elite, you're not.)
Now these classes are ones you CAN use as insults if you can't be bothered to understand their meaning.
handicap
Your average idiot and the bottom of the food chain. Every other mentioned class exhibits many handicap-like traits. Offenses include misspelling, posting in wrong sections, not reading/understanding or more commonly not reading and lying about it, posting nonsensical gibberish, failure to be reasoned with, etc..
Disposal:
Usually they quit once they realize everyone hates them, and usually they come back as Attention Whores and sometimes as weak Trolls.
Attention Whore
That desperate guy that will do anything for a quick shot at fame or some other nonsense. Offenses include making content-less "Look at me!" threads, making E/N threads, ragequitting, stirring up drama over a "serious issue" for them anyways, etc..
(E/N is essentially stuff like "My life sucks, blah blah blah, don't give a stuff about your opinion since my life sucks")
Disposal:
One of the dominating classes in this community, they're everywhere. Many are fairly quiet Superstars that suddenly explode out of nowhere over nothing. The best way to deal with these idiots is to ignore them.
The Thread stuffter
Their actions revolve around turning a thread into a party thread. In some cases their actions are supported by the community but it is generally frowned upon so be careful. Offenses include derailing topics, spamming, "posting for the sake of posting", bandwaggoning stuff (never use this word, don't even try understanding it. You guys butchered it enough already), etc..
Disposal:
Report them and get them banned if you can, it is very difficult to defend yourself against these pricks. The best and only good way to deal with them is to continue the thread like they're not even there.
Now the big words, use only if you know what you're doing
Troll
Their actions revolve around making people miserable for their own entertainment. Unlike Attention Whores they don't take anything seriously at all. Offenses include insulting people as a whole (mass flaming), playing people for fools, baiting, causing uproars, generally posting with the hard intent of making people upset.
NOT TO BE CONFUSED WITH handicaps OR ATTENTION WHORES. Neither of these intend to make people miserable, you just get miserable on your own because you're easy to upset and you're probably a drama-whore/handicap yourself.
Disposal:
You can "Break" Trolls by getting them to start taking stuff seriously or by generally outwitting them. Flaming them gives them what they want, so insults should be left out. If you start getting upset at them, you muse, abandon ship and leave the Trolls for the Forum Elites to handle until administrators ban them.
White Knight
Generally a White Knight defends people for the sake of defending someone. They are always horribly misinformed and tend to "jump" weak trolls and such only to escalate the flamewar. Offenses include defending handicaps, defending Attention-Whores, defending Trolls, etc..
Disambiguation:
It's a term given to those that spend an arduous amount of effort defending stupid girls on a forum in the impossible hopes of getting into their pants. A proper case of White Knight in this definition has never been found on the Blockland forums. However I started using the term with the assumption that people on here were gay for each other, just to add some insult to injury.
Disposal:
You can defend yourself against White Knights fairly easily, simply by standing your ground. White Knights are paper thin and the only reason they bother standing up for people is to gain some rep with that single person. The problem is they only have a very vague idea of what's going on so once they affiliate themselves with the person they're defending it usually get's worse for that person under scrutiny. Therefore sometimes (very rarely) you can see White Knights getting bashed by the very people they're defending.
tl;dr don't use any of these terms unless you know what you're doing. You'll only be frowned upon and classified as a handicap.