From approximately 1975 to 1986, Victorinox Swiss Army knives came with a partially square Phillips head screwdriver. This version was similar to the previous vintage screwdriver, but it didn't have a file cut into one of the flat sides. The square Phillips driver was replaced with the modern rounded Phillips screwdriver in 1986.
Uses: You can use the square Phillips screwdriver to drive any Phillips head screws. The only difference from the modern version is that it fits more cleanly into its knife slot, so it is less likely to fill up with pocket crud.
This tool was common on 84mm and 91mm Victorinox Swiss Army knives, from approximately 1975 to 1986.