for Arrow there is a specific semantic for trade, sometimes there is the point
of view of the seller, sometimes from the buyer (and even sometimes it's only
internal movement, I didn't worked on it yet). So here for every field about
source/destination, I use 2 different names with "sale" or "purchase" inside:
Please try as much as possible to utilize prefix which are consistent with those
defined in business_fields of the Glossary.