Portability Ruling?

Someone want to explain this one?

• The Lodge was recently made aware of an Illinois Appellate Court ruling that should prove to be very important to some of our members. The court held that the language of the Pension Code mandates that a Chicago police officer is entitled to credit for the service he rendered as a Cook County sheriff's police officer and correctional officer for the Cook County department of corrections prior to his employment with the Chicago Police Department. The Lodge has instructed its attorneys to research the ruling for applicability to officers that previously worked for Cook County and other agencies. Further updates will be forthcoming here and in the newsletter.

Here's a link to the ruling itself. It's only 9 pages long, so it's a quick read. It appears to cover the recent Pension Portability ruling - but only if you served as a Cook County sheriff or correctional employee.

So if this exists, is the only purpose of the Pension Portability legislation to cover other law enforcement service? And why wouldn't it already be covered under the Circuit Court ruling? Can someone explain it in simple terms to us?