Police ranks are a system of hierarchical relationships in police organisations. The rank system defines authority and responsibility in a police organisation, and affects the culture within the police force. Usually, uniforms denote the bearer's rank by particular insignia affixed to the uniforms. Most of the police forces of the United Kingdom (including those of the British Overseas Territories and the Crown Dependencies) use a standardised set of ranks. However, as law enforcement in the United Kingdom is organised separately in the three jurisdictions of England and Wales, Northern Ireland, and Scotland, and as most law enforcement is carried out by police officers serving in regional police services known as territorial police forces, some variations in rank organisation, insignia and responsibilities may occur within the United Kingdom. An example of this are the slight variations in the most senior ranks of the Metropolitan Police and City of London Police. Parallel to the regional services are UK-wide agencies, such as the British Transport Police and the national specialist units of certain territorial police forces, with a possibility of further variations. Due to policing in many countries developing from military organisations and operations, police ranks in many countries follow a logic similar to that of military ranks. Most of the British police ranks that exist today were, however, deliberately chosen by Home Secretary Sir Robert Peel so that they did not correspond with military ranking. They were enacted under the Metropolitan Police Act 1829. History of police ranks All police forces have used a wide variety of ranks to meet their organisational needs, especially the Metropolitan Police Service. Ranks have been created, abolished, amalgamated and sometimes revived during the history of British policing. In the following table, "MET only" means those ranks are specific for the Metropolitan Police. Powers In law, every attested police officer is a constable whatever their actual rank, in the sense that officers of any rank have the same powers of arrest. The basic police powers of arrest and search of an ordinary constable are identical to those of a superintendent or chief constable; however certain higher ranks are given administrative powers to authorise certain police actions. In England and Wales, these include the powers to: authorise the continued detention of up to 24 hours of a person arrested for an offence and brought to a police station (granted to sergeants and above at designated police stations), authorise