section 18 (1) PACE house searches (granted to inspectors and above), or extend the length of prisoner detention to 36 hours (granted to superintendents), extend the length of bail from a police station to three months (granted to superintendents) In relation to police officers of the Home Office or territorial police forces of England and Wales, section 30 of the Police Act 1996 states that "a member of a police force shall have all the powers and privileges of a Constable throughout England and Wales and the adjacent United Kingdom waters". Police officers do not need to be on duty to exercise their powers and can act off-duty if circumstances require it (technically placing themselves back on duty). Officers from the police forces of Scotland and Northern Ireland and non-territorial special police forces have different jurisdictions. See List of law enforcement agencies in the United Kingdom, Crown Dependencies and British Overseas Territories for a fuller description of jurisdictions. Detective, reserve, training and temporary ranks Detectives Officers holding ranks up to and including chief superintendent who are members of the Criminal Investigation Department (CID) or Special Branch (and certain other units) have the prefix "detective" before their rank. Due to the nature of their duties, these officers generally wear plain clothes (except for ceremonial purposes) and so do not wear the corresponding rank insignia; however, they still operate within the same structure as their uniformed counterparts. In the United Kingdom, detective ranks are not superior to those of uniformed officers and a detective has the same powers and authority as a uniformed officer of the same rank. The "detective" prefix designates that the officer has received suitable training and passed related examinations to conduct criminal investigations. Special constables There are various grades of special constable which assist in the tasking and management of the constabulary. The ranks are management grades; those holding them are not "sergeants" or "inspectors" for the purposes of the law (for example, authorisations to order the removal of disguises or to set up roadblocks). Originally, specials held the same ranks and used the same rank insignia as regular officers, but there was a general shift to distinct terms such as "area officer" and "divisional officer" in the 1980s. However, since 2000, the National Policing Improvement Agency has encouraged special constabularies to return to rank structures and epaulette insignia identical to their regular counterparts. Although most forces have