The C nonimmigrant visa category is reserved for nonimmigrants who are in "immediate and continuous transit" through the United States. Such immediate and continuous transit may be for:
(1) crewmen who are coming to the United States to join vessels or an aircraft (these individuals may be issued C and D visas concurrently depending upon the circumstances);
(2) persons covered under the United Nations Headquarters Agreement (individuals who are performing services for the United Nations or an ancillary agency of the United Nations).

The C nonimmigrant visa category may be granted to a foreign national for "immediate and continuous transit" for a period of time that is not in excess of twenty-nine (29) days. While the C nonimmigrant visa category is not likely to be one that is often encountered by the immigration practitioner, the regulatory criteria for this nonimmigrant visa category can add to the arsenal of potential options that exist for a client, whose proposed temporary stay in the U.S. may potentially be covered by the C nonimmigrant visa regulations.