1. Any period of service completed by a person in any rank in the Police Service of Northern Ireland.
2. Any period of service completed by a person in any rank in a police force in Great Britain.
3. Any period of service completed by a person in any rank in a constabulary mentioned in regulation 39(2)(1) of the principal regulations (service in the Ministry of Defence Police or Port of Tilbury Constabulary).
4. Any period of service such as is mentioned in regulation 41(1)(a) or (c) of the principal regulations (overseas police service).
Regulation 39 was amended by S.R. 1997 No. 362 reg. 4