The batch process is tricky.
When we import a document, it may have any number of external references that
need retrieving and resolving.
As they are found, they are added to a queue.
As the queue is processed, it in turn adds more references…
Following is a list of the cannonic keywords used in the expected source
files to represent parent-child relationships and other attributes. These
words based on one selected govt vocabulary, many others are likely.