This may be comploetely obvious but I am confused. On my Matrix's NX-26. There are 3 needles correct.

1. IDLE SCREW: Black angled screw under the carb opening.
2. LOW SPEED NEEDLE: Vertical brass screw on side of carb.
3. HIGH SPEED NEEDLE: Needle inside brass fitting coming out of top of carb at 45 deg angle.

The reason I am asking is I read about and people talk about a "low" a "mid" and a "high" needle. I get confused as to whether the "Low speed needle" is also the "idle needle" and is the "mid" is also the Low speed needle?

I am worried that somehow I am missing a needle on my engine!.
I realize its probably an over obvious question as I am pretty sure there are only three adjustable needles on my NX-26. Idle. Low and High.
any info to help straighten me out would be great! thnx