ard less ▁of ▁discipl ines ▁and ▁maj ors ), ▁usually ▁after ▁three ▁years ▁of ▁service , ▁once ▁his ▁or ▁her ▁overall ▁performance ▁and ▁ability ▁meet ▁operation ▁needs , ▁recommended ▁by ▁his ▁or ▁her ▁team ▁leader ▁or ▁a ▁higher ▁command ing ▁officer , ▁may ▁have ▁chance ▁to ▁get ▁promoted ▁( as ▁sub - unit ▁commander , ▁detect ive ▁super visor , ▁etc .). ▁ ▁Offic ers ▁at ▁this ▁mid - rank ▁level ▁play ▁very ▁important ▁roles ▁as ▁the ▁" cor ner stone " ▁of ▁the ▁national ▁police ▁force . ▁As ▁most ▁of ▁them ▁have ▁already ▁served ▁quite ▁long ▁years , ▁with ▁accum ulated ▁work ▁experiences , ▁no ▁matter ▁standing ▁at ▁command ing ▁or ▁non - command ing ▁position , ▁they ▁are ▁either ▁undert aking ▁major ▁respons ib ilities ▁in ▁public ▁security ▁or ▁n urt uring ▁young ▁officers ▁with ▁self ▁model ▁behav i ours ▁and ▁proper ▁instructions . ▁ ▁Junior ▁officers ▁ ▁Lo yal ▁and ▁qualified ▁officers ▁with ▁no ▁mis con duct ▁record , ▁are ▁el ig ible ▁to ▁att ain ▁rank ▁promotion ▁at ▁every ▁three - year ▁of ▁service ▁( only ▁applicable ▁from ▁PC ▁ 2 nd ▁class ▁to ▁S gt ▁ 1 st ▁class ). ▁Rank ▁does ▁not ▁have ▁any ▁connection ▁with ▁position , ▁it ▁can ▁only ▁shows ▁how ▁many ▁years ▁you ▁have ▁been ▁work ▁for ▁police ▁unit . ▁ ▁People ' s ▁Ar med ▁Police ▁The ▁People ' s ▁Ar med ▁Police , ▁as ▁part ▁of ▁the ▁People ' s ▁Liber ation ▁Army , ▁uses ▁the ▁same ▁ranks ▁and ▁uniform ▁as ▁the