Fluorescent marks are the invisible phosphor dyes on banknotes that glow under UV or blacklight. Fluorescent prints are among the security features used in currency to deter counterfeiting (although counterfeiters are already able to imitate them). These are what cashiers look for when they hold down a banknote under a "counterfeit detector" which is actually a small black light.
These marks are not new, in fact we have previously written about fluorescent printing. However the New Generation Currency have interesting fluorescent marks that are worth another feature.
Bonus trivia! Did you know Philippine passports conceal intricate and beautiful fluorescent marks, many of which are also found on Philippine Banknotes? Among them are Malacanang Palace, Mayon Volcano, Chocolate Hills, Barasoain Church, Sampaguita, and Sarao Jeepney.