I have added a couple of extra fields for books, such as "Translated by" and "Other Contributors". I am trouble figuring out how to suppress the punctuation around these fields if they are empty. From my reading of the manual, it looks like a tilde around the punctuation should be enough to suppress it, but this doesn't seem to be working for me. Here's what my Field Order looks like at present:
Better off avoiding the tilde (which is there for backward compatability). I'd stick with the $ quote and/or conditional groups, both of which are easier to understand. Off the top of my head (you can modify as needed):