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.