Three codes could be found in the SIGNUP SHEET FOR CHICAGO INGRESS RPE post on the Investigate Ingress blog.

[1] .eq93olaj.229py

[2] gqxjgeeprssoplichciu

[3] co4kb6do5y94tv

Code #1

Observations

You just have the wrong keyboard

Code #2

Observations

Try to spot the keyword, then it’s easy

Code #3

Observations

14 characters with the right amount of numbers for a valid passcode