There is 4 ranks within CoP starting with TPE going all the way to SE.
When you First join CoP you will be a TPE where you will need to get a SPE or SE to shadow you for a Interview, Basic and a final exam. After you have been shadowed DM a member of Cop Command and they can move you to a PE.
You can find more infomation about what are in the Ranks and a link to the Folders on the page for the rank.
The ranking system is as follows: TPE, PE, SPE, SE.
When you rank up within CoP, you will be able to do additional trainings. When you get SPE, you will be able to do Glock trainings, Field Operation Training and shadow new TPES. After is SE, where you will be able to do Shotgun trainings as well as CoP trainings, SPE induction and SE induction. For information on those ranks they can be found on Senior Policing Examiner and Specialist Examiner.
SE:4
SPE:3
TPE/PE:2
When you rank up to PE you will be able to give/remove roles for PCSO/SO's for the entirety of there procedures. If you are not to sure how to give roles or what ones you should be adding you can find under each the info channel for Interview, Basic Training, FO Training, Ridealong and Final Exam.