 If you've ever transited through Ben Gurion Airport near Tel Aviv, then you're probably aware of the intense security practices being operated there. These security practices include brief in-person interviews for everybody wishing to leave the airport, designed to ascertain the purpose of their travel and to pick up on any suspicious body language. While many passengers complain that these checks are invasive and prejudiced against certain ethnicities, they have almost certainly contributed to the airport's reputation as the most secure air travel facility in the world. One part of the security procedure is the infamous stickers, which get affixed to travellers' passports after going through the initial in-person security vetting. If you don't know what I'm talking about, then look at the back of your passport the next time you fly out of Tel Aviv and once you've had your in-person interview. The sticker contains a numerical sequence, sometimes prefixed by a couple of letters in Hebrew. Previously, the sequence has contained 10 digits, although sometimes it now seems to contain 7. These passengers have speculated as to the significance of these stickers and the numbers they contain. They're understood to relate to the security process. Travellers have speculated that the first digit in the sequence contains your perceived threat level on a scale from 0 to 10. You can find threads on Reddit and other websites speculating as to the system being operated. Some believe that 3 is the category for low-risk foreigner. My last sticker, as you can see, began with a 1, which would tend to make sense given that I'm an Israeli citizen and a somewhat regular flyer from the airport. Personally, though, I'm a little dubious as to whether this system is as transparent as people claim it is. My best guess is that the actual perceived threat level is indicated by digit, but that it changes every day or week or some other fixed interval. But of course, this is just my best guess. Thanks for watching. Until next time.