Three codes were hidden in the ONCE UPON A TIME IN PUERTO RICO post on the Investigate Ingress blog.

[1] 2a2aplekbck3r4r8

[2] 2sex9or9mt7zj5irew

[3] p;j75;rhrly;575io

Code #1

Observations

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

Code #2

Observations

18 characters, right amount of numbers. Same old same old

Code #3

Observations

Those ; are a good indication on how to manipulate the string