Three codes were hidden in the HTML source of the Favors for Friends post on the Investigate Ingress blog.

[1] 537noqcr5553

[2] h,d28Zk;g377,,

[3] uwiruottteytiyuoueyitutptyiiit

Code #1

Observations

12 characters with only 5 letters.

[hint]5 letters is what you need for prefix and suffix[/hint]

Spoiler

We have enough letters for prefix and suffix but too many numbers. Start by splitting the code in 2

537noq

cr5553

Reverse both strings

qon735

3555rc

Looks more and more like a code. Recombine the strings

qon7353555rc

53 is the keyword part. Convert to leetspeak

qon73se555rc

14 characters, the commas give it away.

Spoiler

Those commas give it away as a keyboard flip. So 1=0, q=p, a=; and z=/

gck93/dah844cc

/dah is not a keyword. Notice that the Z which became / was the only capital letter in the code. Shift-/ is ?

gck93?dah844cc

The question mark can be sub by Why to make the keyword whydah

gck93whydah844cc

30 letters. Try to find where they come from !

Spoiler

All those letters are from the first row of letters on the keyboard. Shift them up to numbers and make pairs

72 84 79 55 53 65 86 79 73 68 57 50 56 88 85

Convert decimal to Ascii

HTO75AVOID928XU