I opened up the cover of my Mercury 9.9 today and saw that there were 2
spark plugs connected to the engine. On the sticker it said:

Standard spark plug: NGK BP8HS-15
Suppressor Spark plug: NGK BPZ8HS-15

I read the manual, it doesn't mention anything about the suppressor spark
plug. What is a suppressor spark plug, anyway?

To winterize my motor, do I have to fog oil into both plugs?

Thanks..