In diplomatic usage, Head of Mission is the generic term used to refer to the head of a diplomatic representation, such as an Ambassador, High Commissioner, Nuncio, Chargé d'affaires, Permanent Representative, and sometimes to a Consul-General or Consul. Depending on the context, it may also refer to the heads of certain international organization's representative offices. Certain other titles or usages that would qualify as a head of mission or equivalent also exist. An ambassador, rarely embassador, is a diplomatic official accredited to a foreign sovereign or government, or to an international organization, to serve as the official representative of his or her own country. ... A High Commissioner is a person serving in a special executive capacity. ... Nuncio is an ecclesiastical diplomatic title, derived from the ancient Latin Nuntius, meaning any envoy. ... Chargé daffaires (Fr. ... A Permanent Representative is the head of a diplomatic mission to one of various international organisations. ... See also: consulate (disambiguation). ... Consul (abbrev. ... An international organization (also called intergovernmental organization) is an organization of international scope or character. ...

The plural usage is always Heads of Mission, sometimes shortened in communications to HOM. The French Chefs de mission and CDM may also be seen in the context of the diplomatic corps. Other variations can include Chief of Mission. Deputy Head of Mission or Deputy Chief of Mission and the corresponding acronyms are also used to denote the number two diplomat in service. The diplomatic corps, or in French (formerly the lingua franca of diplomacy; hence the term is still used e. ...

In diplomatic missions and foreign services where Ambassadors may be political appointees, the position of deputy chief of mission may frequently correspond to the senior career foreign service professional, and accordingly be understood to be more than a "deputy."