[TruthSHIFT]

I don't understand what one of the hints means: "One specific dot is included in all solutions imaginable."

[mmanfrin]

Took me a bit to understand it too, it means: Of all the possible permutations that the surrounding dots (of that dot) could be, there is at least one dot that is the same (so that while you can't 'solve' that dot, you can still start to fill out the surrounding).

[T-hawk]

Example, in the top-left corner of the board:

  2 _ _ R
  _ _ _ _
  R _ _ _

The location to the right of the 2 must be blue. If it's red, then there's no way for the 2 to see two blues. That's what it means, that that dot is included in every possible solution for the 2.

[yellowapple]

I think it has something to do with two adjacent "known" dots (for example, I got that on both a 6 and an 8 when both were right next to each other).