In a few of the previous posts you fell mention a Warder file.Searching it app they are just a tapered file shaped somewhat like a sword?

Not sure what you mean by tapered or sword. Warding files have two large flat surfaces that are parallel planes i.e. the thickness between the two flats doesn't taper. They make slits or slots with parallel sides. The other two surfaces (the thin ones) are not usually parallel, so there's some taper with the tip of the file being smaller in that dimension.

I think the name warding comes from the warding grooves in a key to a lock. Imagine having to file that groove — you need the sides of the groove to be parallel.

Warding or keyhole files are old as the hills. Just not common any longer as hand working has long gone away for the most part. Mark's description is a good one, I'll add that the ones I've had seem to have a double or bastardish cut to them. They also have some lengthwise flexibility that more common files lack, for better or not. My understanding was they were for creating slots out of drilled holes. I have a range of sizes and like them a lot for slotting stays and blades for tabbed dropouts too. Andy