Question about patch knives

[tyecop15]

I have attached a link to a picture of two knives they call these patch knives. I've seen many of them and each of them seem to have this cut out the bottom of the blade. Could somebody explain to me what this is used for. I understand the name of the knife came from the patches they cut for muzzleloaders I'm asking about the grooves in the back

thank you

http://www.adriaangerberknives.com/pair_of_patches_1.html

 

[JAB]

That is what's known as a Spanish notch. Some opine that it is designed as a "blade catcher", some will say that it was used for stripping fat off of sinew, while others will insist it's just a fancied-up choil or that it is purely for decoration. Take your pick?

 

[tyecop15]

Thanks for your quick reply I just couldn't seem to wrap my brain around what it was used for.

 

[JAB]

No problem.

Another thing that I remember reading somewhere (which may or may not be correct) is that these notches may not actually be period-correct for the trade knives that they are emulating (it's usually a design feature seen more on Bowies and other larger fighters).