"OK, so the collateral value of gold in this sense is and has always been 85%?"
Collateral haircuts on gold can vary between CCPs and lenders. There are lots that won't accept gold at all.
"Such apparently credible information ie. the article regarding the collateral value of gold doubling with Basel 3 in 2013 is entirely false?"
I wouldn't call it credible.
Think about it. If you we're the a global financial regulator (BIS) and you were about to make a major change to the prudential standards that was likely significantly change the behaviour of banks and impact a major market, would you announce it in a foot note?
All major Basel changes are preceded by discussion papers and feed back from the industry. These are all public documents. If the journalists and commentators who peddled this "gold as Tier 1 asset" story were "credible", they would know that.
