... Codes work whether you’re online or offline, you don’t need an internet connection. Plus Codes are based on a set of 20 alphanumeric characters. They do not include easily confused characters, are not case-sensitive, and exclude vowels. Plus Codes represent an area. The resolution of the area can be changed by adding or removing characters after the “+” sign. Simple, free to use, open-source digital addressing, for the entire world.