Nobody outside Israeli neighbourhood even dares to fake these. Not to say they have no technology to do it. You can sleep calmly having these in collection. I would call it a guideline since fake Shekels are like unicorns. They dont exist in circulation lol.
I have found on internet similar things from Fiji, USA of course, Bank of England and so on. It is good or as good as numista banknote repository. Sometimes numista will not have too detailed info on watermarks, uv light features, while guidelines will have.
Nowadays, banknotes are so sophisticated that risk of getting a fake is zero. From my experience, anything after 1990 is safe. Anything in between 1950 and 1990, you have to do a bit research but still 90 percent safe if buying from reputable source. And yes, US dollars are mostly concern in that 10 percent since they are counterfeiters target.
