Probably insoluble fiber.  Manufacturers have some leeway in the fiber
listing.  Soluble fiber has to be quantified, and total carbs have to be
labelled, but insoluble fiber is left up to the discretion of the labeller.
Some include it and some don't.

>I have a question.  Yesterday I was looking at a package of pistachios and
>it said 9g total carbohydrates, 3g sugars, 3g fiber.  What are the other
>three?
>
>John Pavao