Rear suspension damping setting

[derbyshirebill]

Chatting about suspension spanners reminded me to ask:-
Aunty Vera has a 3 position damping setting on the rear shock, adjustable by screwdriver. Now, I notice that I can keep screwing the adjuster past the 3 settings and just keep screwing. I'm wondering 1.- Is the adjuster supposed to have stops that should prevent it from keeping turning? 2.- Does that not matter because the adjuster is just exposing different oilways, or alternatively 3:- Is the adjuster gradually restricting an oilway the further in it is screwed?
I can't really tell from the 'feel' of the suspension what is happening.

[dpmiller]

It's a needlevalve. You can actually screw it in/ out till it stops...

[everydaybiker]

So it won't screw all the way out accidentally (and then drop out) then?

[tweaker]

No, it won't drop out - not on my bike anyway ;D.
I was a bit puzzled the other day when I decided to "tweak" the damper settings 'cos I expected the adjuster to have detents, which it hasn't and only to be adjustable over the 270° range. - On my bike (a 650-P) the total adjustment is about 2 1/4 turns (i,e, ~800°), but I haven't a clue whether the "standard, hard and hardest" settings are at the screwed in end of the adjustment range, the screwed out end or what ! - Anyone know?
I decided just to set it somewhere in the middle, see what she rides like and will later adjust up or down to see if I can feel the difference .

- Tweaker