The United States Secret Service uses code names for U.S. presidents, first ladies, and other prominent persons and locations. The use of such names was originally for security purposes and dates to a time when sensitive electronic communications were not routinely encrypted; today, the names simply serve for purposes of brevity, clarity, and tradition. The Secret Service does not choose these names, however. The White House Communications Agency assigns them. WHCA was originally created as the White House Signal Detachment under Franklin Roosevelt.
The WHCA, an agency of the White House Military Office, is headquartered at Joint Base Anacostia-Bolling and consists of six staff elements and seven organizational units. WHCA also has supporting detachments in Washington, D.C. and various locations throughout the United States of America.
According to established protocol, good codewords are unambiguous words that can be easily pronounced and readily understood by those who transmit and receive voice messages by radio or telephone regardless of their native language. Traditionally, all family members' code names start with the same letter.
The codenames change over time for security purposes, but are often publicly known. For security, codenames are generally picked from a list of such 'good' words, but avoiding the use of common words which could likely be intended to mean their normal definitions.
U.S. Secret Service codenames are often given to high-profile political candidates (such as Presidential and Vice Presidential candidates), and their respective families and spouses who are assigned U.S. Secret Service protection. These codenames often differ from those held if they are elected or those from prior periods if they held positions needing codenames.
U.S. Secret Service codenames are not only given to people, they are often given to places, locations and even objects, such as aircraft like Air Force One, and vehicles such as the Presidential State Car.