Ask HN: How can I tell if my software has restrictions or tarrifs in China?

I recently had a request from a company in China to buy my software, and they sent me a form asking for export classification, and if I have tarrifs or a restriction code. (I wrote some test software for flash devices.) I have no legal team, and searching the US .gov websites is really complicated. Is there an easier way to figure out if my software is problematic?