Is there a list of the icons and their meanings?

[Millertime]

Getting pretty far into the game I've become confused on the meanings of some icons :) I tried to find a list of them all but with no luck.. does anyone know of such a thing?

Specifically I'm getting confused on the -3- and {3} when over a column vs in a cell, etc.

[LX]

I don't know about a list but just those specific examples: {3} means all the blue cells are beside one another. -3- means there is at least one gap between the blue cells. That applies to both numbers in cells and over the columns

[VoidCog]

At the beginning of each world it gives new instructions at the bottom of the screen in the lower left :D

[Chazz the Elder]

Not quite -- you aren't told what it means when the numbers are angled, you have to guess.

[Millertime]

Yeah I think I have it now.. just got a bit confusing when there were four varieties on the board at once :)

[DivideBy0]

I would recommend just replaying from earlier levels to get the "tutorial" messages and practice applying those concepts on the appropriate puzzles.

[Zwart]

That would be a pretty short list with exactly three entries: plain numbers, {x} and -x-. They always keep the same meaning regardless of their position. If you read the tutorial messages it should be pretty clear.