Is a Pringle a potato chip?

For some reason I found this funny.

Is a Pringle a potato chip? I had no idea it's really only about 40% potato product, but at least in Britain they've declared Pringles are sufficiently like "potato chips" to be potato chips - and to qualify them for $160 million in back taxes on potatoes.

Now my question is this: Why have a special tax on potato chips but not corn chips? Are they possibly clearing the way for Doritos' cheesy goodness to take over the savory snack market?

Here's a similar case this one reminded me of these humorous efforts to define obscenity: "I know it when I see it."