A voluntary standard a producer, site or refiner can be certified against, with its own requirements, versions and holders.
Every record in this group is the same kind of thing, so they sit on one ring, ordered so that records linked to each other sit near each other. Bodies reaching in from outside the group are drawn beyond it.
A link whose validity window has closed is drawn dashed and stays on the map. An expired title or a former operator is a finding, not noise.
Relationships crossing out of this group, gathered by where they land.
The nodes above, as a list. Each one opens the record’s own page, with its relationships and the source passage behind each of them.