It is a 6-digit number assigned by Visa to each acquirer. If a merchant has different acquirers for Authorization versus Settlement, the merchant will have a separate BIN for each one. SIGIS is only collecting the Authorization Acquirer BIN at this time.
Carbon forms a vast number of compounds, more than any other element, with almost ten million compounds described to date, and yet that number is but a fraction of the number of theoretically possible compounds under standard conditions. For this reason, carbon has often been referred to as the king of the elements.
Anyway, the likely reason that green is important is that plant life was a very large part of what we needed to look at for a very long time, and the same for the ancestors of humanity. If you live in a suburb it might be hard to notice, but the natural world is almost entirely green when viewed from a distance.