[1][better source needed] CIA cryptonyms sometimes contain a two character prefix called a digraph, which designates a geographical or functional area.
[citation needed] TRIGON, for example, was the code name for Aleksandr Ogorodnik, a member of the Ministry of Foreign Affairs in the former Soviet Union, whom the CIA developed as a spy;[4] HERO was the code name for Col. Oleg Penkovsky, who supplied data on the nuclear readiness of the Soviet Union during the Cuban Missile Crisis of 1962.
[5] According to former CIA Director Richard M. Helms: "The code names for most Agency operations are picked in sequence from a sterile list, with care taken not to use any word that might give a clue to the activity it covers.
On some large projects, code names are occasionally specially chosen—GOLD, SILVER, PBSUCCESS, CORONA.
When Robert F. Kennedy requested a code name for the government-wide plan that Richard Goodwin was drafting, an exception was made.