Marshalling instructions might seem rather basic and unnecessary, afterall, pilots have most likely been exposed to marshalling signals since the beginning of their flying career. In the United States there are varying levels of consistency when it comes to marshalling and, ultimately, not a great deal of importance is placed on marshalling procedures. When operating internationally, however, it is unusual not to be assigned a taxi stand and greeted by escort vehicle who then guides the aircraft to a marshalling agent. The whole process of parking is much more formal and is usually conducted without two way radio communication. ICAO publishes the correct marshalling instructions and procedures in ICAO Annex 2, appendix 1.