What parts of the MSDN Library can be imported into Unity?

It all started with a CapsLock issue - because you cannot read its current state neither with Input.GetKey(KeyCode.CapsLock) nor Event.capsLock - only you can say is that buton is pressed down. I wanted to use System/Console/CapsLock and written a code:

import System;

function Start () {
 print(Console.CapsLock)
}

and it says: Unknown identifier: 'CapsLock'. Must be a security kind of thing - right? Or I hope I overlooked something. Did I?

Make sure you have the full .NET 2.0 api selected in Edit > Project Settings > Player > Other Settings. It's the Api Compatability Level setting, which defaults to .NET 2.0 Subset.

System.Console.CapsLock works fine for me with a windows or mac target and the correct api selected.

Besides that - there's a number of things that unity doesn't include, which you can sometimes fix by pulling in the relevant dll from a mono install. Not everything will work that way though, so in those cases you'll need to look for an alternative