What does "Heroic Geared" mean?

I see this spam in /LookingForGroup all night long:

LF1M DPS/CC for H SP - MUST BE GEARED!!!

And yet, try as I might, I found it was nigh impossible to figure out what that meant. What is “Heroic Geared”? What is "Kara Geared"? How do I know if I am correctly geared? I'm not in a raiding guild, so it's not like I can just ask on /guild and get an answer.

So, instead, I send out a whole lot of messages like this:

I know I don't qualify, but for my future reference, what is the spell damage or DPS requirement for that?

Whenever I see spam for a dungeon or raid, I ask. I don't always get useful answers, but most of the time it is worth it.

To that end, I've started this page on the Shadowpriest.com Wiki: Dungeon Expectations. But that's a huge page with a bunch of tables, so let me give it to you straight.

For a PUGging Shadowpriest ...

You are ready to start on Kara when you have replaced most or all of your greens with blues. If you have greens then you should have at least as many purples to compensate. You may or may not be hit-capped, but you should be a large way towards it. Your unbuffed spell damage should be close to or above 700. You can pull off 650 if your group is very good. You're going to have trouble pumping out the pure DPS and MP5 that the group needs for the big bosses (Nightbane and the Prince) until you are hit-capped and greenless, so make sure you have as many buff foods, elixirs, and oils as you can afford.

You are “Kara-geared” when you are greenless and hit-capped. You should be standing on 750-800 unbuffed spell damage. At this level you can feel comfortable doing full Kara runs, knowing that you're definitely pulling your weight.

The range for “Heroic-geared” overlaps a bit. You can start doing the easy ones (Slave Pens, Ramparts) around 750 as long as you have a decent group. You're going to want to be closer to 850 if you want to start doing ninja-farming runs that don't take two hours. The Heroic bosses take roughly the same effort as the Kara bosses, but there's a bit less wiggle-room for error as you are running a 5-man instead of a 10-man.

Your goal in Kara and Heroics should be to replace as many of your blues with purples as you can.

The next step at 850 is Gruul, then Magtheridon at 900.

At that point it starts over again for Zul'Aman. If you have an experienced group, you can start running ZA as early as 950. But you'll want to be 1000+ if you're going to farm it efficiently and feel like you are really contributing. You should be almost completely in purples for ZA.