![Chess 492Oc vs SS4K [33] Ah. Also rook trade.](https://cdn2.scratch.mit.edu/get_image/project/1054519879_480x360.png)
That is a pin where the piece that's getting pinned can still move on the file or diagonal it is pinned to. A queen can only be partially pinned on the account of having the movement powers of a rook and bishop at once. A knight cannot be partially pinned on the account of it being a (2,1)-leaper.
