G&L neck shapes

[scalpy]

 Not being technically minded I have majorly procrastinated over setting up my ASAT bass. By years! One of the reasons I bought my Sire v7 was to do a bit of training, got it spot on first time I changed the strings. It would appear this was total beginners luck, the ASAT has been a different kettle of fish. Anyway, having purchased the necessary imperial hex keys for the adjustments, I started with the truss rod. I have no idea if it is a standard arrangement or dual action like my lb100. I was hoping to tell, but got a bit lost. So I took the neck off, which was one of the most terrifying experiences ever, to get the actual date it was made. Turns out it was 2000. It should have a CLF serial number but doesn't. 
 So- does anybody know if its dual action before I go to bassesbyleo, which i find a bit bewildering.
Also, does anybody know what the D means? I can only find references to numbered neck shapes.

Thank you in advance
Harry

[Graham]

Try the guitars by Leo forum, they'll tell you straight away