Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_68 (callsign VARCHAR, icao VARCHAR)
### Question:
Who is the callsign that has ICAO of SCO?
### Answer:
SELECT callsign FROM table_name_68 WHERE icao = "sco"