Ranks
The ministry is very much a paramilitary organization. Its structure is like large metropolitan police department except that it is multinational and has a council that oversee its global policies. Its ran structure is usually the following though titles may vary regionally.
Ministry board member - international council that sets ministry policy. Decisions must be unanimous to become law, policies can be set for a period of a year with a simple majority. Members are elected by representatives from nations participating in the magical non-proliferation treaty.
Director - official from central command. Sometimes sent to audit local ministry units. A director will never audit their home region. Appointed by the board.
Commissioner - member of the ministry in charge of a province or large metropolitan region. Responsible for all local decision making. Locally appointed by the government but the board must approve candidates before the position becomes official.
Deputy commissioner - second of command for large region. Often charged with making budgetary decisions. Appointed by and paid for by the ministry board. Almost always from a different nation/region than the one being overseen.
Commander - charged with a division made up of several precincts. Hired by Commissioner.
Captain - oversees a precinct and a police station. Often elected locally.
Lieutenant - supervises an entire watch shift of a police station or detective squad (Apothecary, Magical Homicide, etc.) Usually has 2-5 sergeants reporting to them.
Sergeant - officer who supervises a squad. May oversee an entire shift when lieutenant is unavailable.
Inspector - An investigatory specialist, usually working in plain clothes. There are often several pay grades but inspectors do not outrank officers albeit they are often senior in years of service and so have a certain degree of authority beyond police officers in specific situations. Commonly an inspector will be in charge of cases.
Officer - A regular ministry official whom wears no rank insignia. There may be several pay grades depending on duties.