Some Basics
The 9XXX series are "command" meaning PPB lieutenants and up. So that is what the 9 at the beginning means. Next is the precinct assignment. So 98XX would a Central Precinct command officer, as the Central series (and districts) are 800's. Here's another example: 99XX - that's an East Precinct command, etc. The final two digits are individual designators for that particular person.
Basically the same thing for PPB sergeants, too. 3XXX are sergeants. 38XX is a Central sergeant. 35XX is a North sergeant, and so on.
Command numbers are individually assigned and remain with that person for as long at they are assigned to a particular precinct, unlike an officer that is assigned the district number of their assignment as their call sign, and is subject to day by day change depending on which district they get assigned to by their supervisor.
PPB Traffic call sign designators (1XXX) are like sergeants and command, except that Traffic numbers do change depending on area of assignment at the beginning of the shift. Traffic typically floats all over the city though, regardless of initial assignment, and can get confusing. A Traffic car might be 17XX (Traffic East Precinct). Now lets say that 17XX is the last traffic car out city-wide and a call comes to evaluate a DUII driver traffic stop made in deep SW Portland (in Central) by the district car there. The 17XX unit keeps it's East designation, even as it drifts over to Central net, or where ever else it goes for that shift, all over the city if necessary (because the demand for traffic units city wide is high and they are often called out of their assigned precinct). That is how you can hear an East traffic bike or car come up on some other precinct's TG responding to a call there, but keep it's radio ID as a unit from outside that precinct.
I was taught all this while a PPB reserve. Unless it has changed in the meantime it is still like this. And here's another tidbit... the PPB reserves has it's own version of "command" as well, with a reserve lieutenant, captain and the like. Oddly enough, reserve lieutenants and up get to use the same 9XXX command series call signs that the full-time PPB lieutenants and up also use. Sure pisses some of the regulars off! And I can understand why! Reserves are 700 series, so a reserve lieutenant and up would be 97XX.
Like it said in mikepdx's post above, look in the RR Wiki he linked to, and apply the information from my post to that information. That will give you the answer.
Happy scanning!
