Thank you very much Zifir, 
 
This is very helpful. I have also seen the symbol one other yataghan blades, even though it is not a very common one. I did not know of its significance by now though. I gues if it is indeed a Bektashi symbol, this would simply mean that the owner or the maker (Halil) has some sort of a Janissary connection. 
 
Hopefully, we will be able to learn more about the circles at some point. 
 
Regards, 
Teodor
		 
		
		
		
		
		
		
		
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