[Dx-qsl] help for prefix counting needed

[DE1DXX at aol.com]

Hello to all,
 
I've just began to count my verified prefixes, but I need some
help with  the counting and some callsigns.
 
If I have 6W/ON5TN verified, to what prefix does it belong,  because
there is no second number in the prefix (like 6W7RV, counting as  6W7)
Same with 9A/... ; A4/DL1HRN; EA/PA1RHO/p, FG/N4CD and so on.
Is the  second number generally a 0 (zero)?
 
And how counting calls like BA4RF/1 (= BA1  ?)
H79W/YN4     (=YN4)  ?
UA3YH/0      (=UA0)  ?
8S4C/5       (=8S5)  ?
R3RRC/6      (=R6)   ?
JH4TEW/4     (=JH4) ?
 
But what about 
FR/F6KDF/T      (Tromelin  Isl.)
XF1/F5TYY/XF3   (Mexico  NA-135)
D70YT/5          (AS-081)
W1AW/90         (just a  W1)  ?
OE5XCL/90KK     (just a OE5) ?
 
Help would be highly appreciated. Many thanks indeed!
 

vy 73
Andreas - DE1DXX
 
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Andreas Ibold  - Alpen - GERMANY
SWL DE1DXX
JO31GN DOK L14 CQ14 ITU28
Pse, do not  forget me... I need YOUR QSL.... :-)))
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