I am making, or trying to, a pair of knitted bootees for myself. I am having trouble understanding some of the directions. 
On Row 7 it says as follows: With Color B k 8, dec 2 sts, k 17, dec 2 sts, k8. (OK. I understand so far.) Continue in this manner to work 2-sf every other row above previous dec and alternate colors....... What does 2-sf mean? Is it a misprint? What? If necessary, I could post the whole pattern if that would help. Any help would be appreciated.
	
		
			
		
		
	
				
			On Row 7 it says as follows: With Color B k 8, dec 2 sts, k 17, dec 2 sts, k8. (OK. I understand so far.) Continue in this manner to work 2-sf every other row above previous dec and alternate colors....... What does 2-sf mean? Is it a misprint? What? If necessary, I could post the whole pattern if that would help. Any help would be appreciated.
 
	 
 
		 
			
		
		
		
	
	
			
		 
 
		 
 
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		 
			
		
		
		
	
	
			
		
 
 
		 
 
		 
 
		 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		