Despite this, the Borg used an alphanumeric code as their written language and for encoding and transmitting data throughout the Collective. This language consisted of circular symbols with geometric shapes cut out of them. These symbols could be seen on various control panels, labels, and viewscreens within Borg structures. It was written in many different directions: in horizontal lines going from left to right and right to left, and vertically. As the name suggests, the symbols represented both alphabetic characters that represented sounds, and numbers, with much Borg terminology comprising alphanumeric sequences.
The code was immensely complex and consisted of at least fifty characters and was stored, among other places, in data nodes. Despite its complexity, other species could learn it. (VOY: "Revulsion", "The Raven")