U+0040 "@" Commercial At Unicode Character

U+0040 "@" Commercial At is a typographic symbol originally used in commercial accounting and invoicing to denote "at the rate of," a function it still retains in pricing contexts. Its modern ubiquity stems from its adoption as the key separator in email addresses, where it distinguishes the user name from the domain name. This role, established in the early days of internet messaging, has made the at sign one of the most recognizable and technically crucial symbols in digital communication, also finding widespread use in social media for mentioning users and in programming for array annotation and decorators.