I know I know, its not really a thing, but it is the first one I have seen in the flesh and it looked interesting enough.
It's like a Palindrome for numbers. Ideally all 8 numbers in the note would read the same forwards or backwards. This only has the last 7 numbers that read the same forwards and backwards though. Since it is mostly all 1s though it looks pretty decent.
haha...I believe palindrome is only 4 digit(radar)...anyway its a good find and only 1's and 8's so keep it