SLV Database 5 - Dark Bullion

Dark, I'm feeling Dark. Go ahead, bite me.
This is the fifth major article in the series of SLV bar list data analysis. I've become so obsessed with this bizarre niche topic that between the pills and the lingering after-effects of the last round of mystery drinks at GM's country mansion, not an hour goes by where my reprehensible soul* is not pondering what mysteries can next be pulled from the darkness of the void.

The concept of dark bullion was first written about in analysis #2 where it was noticed from the SLV data that some of the bars appearing as 'new' inventory had actually been listed some time prior. In analysis #3 and #4, we progressed the investigation and now we know that bars can go dark and resurface, sometimes reappearing in different vaults (and we can track their movement from London to Australia, for example). Hidden, juicy secrets! Exactly what are those bars are doing when they are not represented on an ETF's bar list? While we will never know, at least we can describe what we can't see!!

Let's start with a premise. The "Dark Inventory" concept in commodities is not a new one ¹ but it is fair to say the area is difficult to study because of the general lack of quality information. However, the silver and gold inventories provide an interesting opportunity to track inventory because (conveniently) each bar has a serial number. So ... what is available to find, and how do we find it?