That means that item is Taxable.  This just started happening me.  It's on all items (products, services, etc.), even those that are not even set up as taxable, and the taxable box is not checked on the line.  It shouldn't be there.  The templates also changed to include a tax line total, even though it's zero (because it wasn't a taxable item).  I haven't heard what happened nor how to fix it.