German East Africa, variants without explanation [opgelost]

https://en.numista.com/catalogue/pieces11912.html
https://en.numista.com/catalogue/pieces37340.html

these two coins have different variants called obverse A and B and reverse A, B and C. But how can I know what is what without a description?

Reverse should be clear from the redundant additional description, A = one hooked and one curled L, B = triangular bottom of Ls, C = two curled Ls
But what is obverse A and B? The two coins have different obverses anyway, so are there 4 different obverses?

Hi

I've put in the comments how to recognize the different variants:

Different variants exist :
Obverse A : big crown
Obverse B : small crown

Reverse A : Curled tip on second L
Reverse B : Pointed tips on L's
Reverse C : Curled tips on L's

 

So the one I have tend to be B and B!
Thanks for the explanation!

I can only see one kind of crown for KM# 15 and one different kind of crown for KM# 15a.
https://www.google.de/search?q=doa+20+heller&tbm=isch
On KM# 15, the crown is bigger than on KM# 15a.
So what is a big and a small crown?

KM# 15 (big crown) (so this is 15a!)


KM# 15a (small crown) (so this is 15!)

According to the Krause, Km#15 is copper and KM#15a is brass, but there is Obverse A and B for the two coins :

Ah, thank you, I was thinking the size of the 1916/DOA is the difference between the main numbers