There are incident codes that have been assigned to various duties officers perform, there are fair codes, training codes, range codes, truck inspection codes, K-9 codes and even a code for air speed or road side safety checks. As previously posted some of the I- Ida (incident) codes are the same number as associated with IVC or Criminal code violations. I-Ida is the phonetic alphabet word so is commonly used with Incidents or Investigations.
Prior to using the current C-computer A-aided D-dispatch Il State Police used the T.I.P.S. System for tracking payroll/time utilization/activity. There were numerical codes such as 101 for rural patrol, 102 for interstate patrol, 106 for traffic stops and the 800 codes like 859 for wanted on warrant.
The radio procedures changed with the roll out of the Open CAD system and determination of TIPS. The Open CAD system was an off the shelf program the state purchased and was also utilized by Chicago PD. The TIPS system was a program the ISP had developed for the ISP specific needs back in the early 70's.
With the change to Open CAD there was more plain language and fewer number codes. Instead of going 211 for fuel the Officer advises equipment maintenance. Instead of going 101 the Trooper says Patrol other or FTO supervision or whatever his task.