Unlike Roman, Maya or Iñupiaq numerals, this isn’t a total reimagining of numbers. Instead, it’s an uncanny parallel universe. Any number without zeros retains its old appearance (1,776 is still 1,776 ...
One of the major mysteries in Yellowjackets, over the two seasons that the series has aired, is the symbol. It seems to depict an impaled human figure (probably female), with a hook at the bottom.