Flagging is used to describe a type of stone. Per the dictionary “Flagstone is usually a form of a sandstone composed of feldspar and quartz. The material that binds flagstone is usually composed of silica, calcite, or iron oxide. The rock colour usually comes from these cementing materials. Typical flagstone colours are red, blue and buff, though other exotic colours exist”.
Flagging sandstone in not usually straight lines, hence the paving style we refer to is ‘crazy finish’. These are generally laid on a bed of sand/cement.