This is a format created in the Acorn Draw program, intended for image visualization by using vector lines. It’s used for storing information in the publishing business (brochures, logotypes, etc.). The main advantage is it’s high quality source images when printing. It’s been in use since 1980.
Storage format for images that can be used as graphic textures in 3D applications or computer games. It is also used in the CorelDRAW software as a Pantone Spot reference palette element for the purpose of applying colors to editable elements.