Three codes were hidden in the HTML source of the PRECURSORS post on the Investigate Ingress blog.
[1] 3jlp2shldx4d2l
[2] $$@#$#!$%!@!@$@$##%!!%##@$$@@$!!$$%@%#@!#$##
[3] 3guj4xskenyot9j4x
Code #1
Observations
Passcode format is there, an old roman emperor will guide you
Code #2
Observations
Check the range of those symbols
Code #3
Observations
Passcode format is there, go through your usual cipher routine