PT question: what is the little oo thing?

[Pokerdemic]

I just bought poker tracker last week. I've been searching their forums and here to figure this out, but I can't find anything. For a bunch of the players I have hands on, their aggression factor for different streets is oo. This is not two zeros, but two of the letter o. Anyone know?

[-phish-]

00 = infinite

it means that they never called a bet on that street.

[Pokerdemic]

thank you