When Canada started assigning three letter codes to airports, very few foreign airports began with “Y”, so Canada put a “Y” in front of each nearby train station code to create the airport code and to differentiate it from U.S. airports.

Calgary is known as YYC because that is the official International Air Transport Association (IATA) location identifier for the Calgary International Airport. In the 1930s, Canada adopted a unique system for its weather-reporting radio stations and airports. Originally, two-letter codes were used, but a "Y" was added as a prefix to indicate that the station was co-located with an airport. For Calgary, the "YC" portion was its existing identifier (derived from "C" for Calgary), and the leading "Y" was added to satisfy the Canadian naming convention. Over time, these three-letter codes became deeply embedded in the local culture of Canadian cities. In 2016, the airport was officially renamed YYC Calgary International Airport, solidifying the code as a central part of the city's brand. Today, locals and businesses use "YYC" as a shorthand nickname for the city itself, appearing on everything from social media hashtags to local merchandise.