Crafting guide for furnace fuels is misleading

The crafting guide for fuels is misleading. The problem is that it looks exactly like an ordinary crafting recipe, when it fact is only for fuel which is a difference.

 I initially thought I have to combine a furnace and dirt in the crafting grid, but I figured it out later. The crafting guide makes no difference between furnace fuels and actual recipes, so I think it could be improved.
