Idea of Additional Icon
The icon is very simply composed of an empty circle with a large, upper case letter A in the center, about as wide as the circle's radius. The icon stands for the presence of additional elements outside of the ones currently being represented on the screen.
This is the Additional icon for Windows 10
. Here we go. Optimized for 32x32 px, these are the simplest icons in the line style. Downloadable formats are PNG and SVG, among others. Icons8 icon pack is unique in providing a huge number of icons designed by the same team of four designers who create the new icons every working day in the same style and with the same quality. Same cool as the Bat Face, huh.