In fact, the agreement doesn't exactly say that you can't give a subsidy or a benefit. It says you can't give a benefit, direct or indirect, that reduces the burden of the export tax, the export measure, the export charge, because on the U.S. side of the border they wish to see us impose this charge to level the playing field--at least in their minds--with respect to the competition in lumber.
As I said earlier, there are two or three kinds of subsidies that are sheltered under the agreement, subsidies that existed prior to the agreement, that address issues of forestry management or that go to first nations, for example. But otherwise, almost any other kind of subsidy could be challenged by the U.S. under the agreement.