One of the projects we work with at Devies is related to the dental domain. In that project we use the dental notation (ISO 3950) to refer to teeth. Every tooth have an unique identifier that consist of two characters. The first character represent a quadrant (one of four areas in the mouth). The second character is an identifier that refers to one of the eight teeth in that area.

Early on in the project we represented the tooth identifier using a string, for example "42" (4 is the quadrant, 2 is the identifier). As the project grew we stared to use this tooth identifier in many different places in the project. Since we use a raw string, we had to make sure the tooth identifier was properly validated at every place where it was used. Additionally, it was unclear what the tooth identifier (string) represented, and it affected the readability of our code.