A collar number, also known as a shoulder number, force identification number (FIN) or occasionally as force number (although this can also refer to ID number of a force itself), identifies police officers, police community support officers (PCSO), Special Constables (SC or SPC) and some police staff in UK police forces. Although now displayed on epaulettes (i.e. on the shoulder), it is still commonly referred to as a collar number. Although most forces issue a collar number to all warranted officers, regardless of role, only uniformed officers of the ranks constable and sergeant actually display the numbers.