Need Help Setting Fork Oil Level

I've always measured oil level with the fork compressed, springs removed and rebound piston rod fully UP. [my old KX manual shows it this way] My new bike's manual hints at setting the level with the rebound rod in the fully DOWN position but doesn't actually specify. Neither Eric Gorr's nor Race Tech's lit. mentions the [proper] rod position when measuring and the difference in oil levels is 20mm -depending whether the rod is up or down. Which do you think is correct? [These are conventional right side up cartridge forks - KDX 220]

Thanks guys. Maybe that's why my suspension's never bottomed out all of these years. I just filled it with with the rod down & will see how it works. Worse case --I pour in a couple more CCs oil. I reviewed my Race-tech suspension video and Paul is measuring the oil level with the rebound rod in the compressed position [upside down Kayabas]. By the way, this video and Eric Gorr's suspension video are both excellent step-by-step tutorials for anyone wanting to learn how to & rebuild their own forks.