Recently, U.S. National Economic Director Gary Cohn and Treasury Secretary Steven Mnuchin revealed a few details of President Donald Trump’s tax reform plan. While many of the ideas were similar to Trump’s promises while on the campaign trail, Cohn and Mnuchin emphasized that many details of the proposal still need to be negotiated. In fact, the outline of his tax proposal was significantly less detailed than the plan released during his campaign, comprising just one page filled with bullet points. Here are the five biggest unanswered questions about Trump’s tax plan so far.