Here's a list.
There are different levels of appreciation, from Know-That to Know-How
- I've heard of it...
- I can recognise it in a position or a game
- I pay attention to it when choosing a move
- I know a model game = I know enough about it to win a game with it when it is the main thing going on = I can make an effective plan based on it
- I can judge how important it is in a more complex position
Bishop pair (two Bishops)
classic (Italian) diagonal
Greek diagonal
half-open file
long diagonal
open file
pawn lever see pawn break
pawn: isolated Queen's (IQP)