Going forward, I can tell I'm going to need more space to explain and identify the rules behind a number of equipment pieces I include in my game - particularly those associated with herbal medicine and the apothecary. I've never functionally sat down to fix the rules behind these things, except by general agreement, but it seems to me that the best way to do so would be to make it a part of the wiki.
Thus I've created this page as an index. There's not much there just now, just three things; but I will update it continuously over the next few weeks as I work on fixing the general equipment table. I can see this list expanding into a very large list.