The word "interpretation" is just a way to avoid the longhand of "The judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution, the Laws of the United States, and..."
No matter how clear or unclear the wording of the law, someone has to be granted the power of decisions about it, and in the US that power is vested in the courts. In trying Case law part of the decision is whether or not the 16th IS law. The courts have decided that it is, again and again.
Here's a good summary of how the courts have decided on this matter.
Gotta be clear, I personally don't mind you not paying, and I like tax protest. I was kind of hoping that the "Not In Our Name" people would extend their protest to "Not With Our Money" because I think that would make some very interesting statements.
But the only thing keeping you out of jail, really, is the blessed incompetence of the IRS -- not some voodoo misinterpretation of how the law works.