The Fibonacci Numbers can be defined in different ways.
$$F_0 = 0; F_1 = 1$$
$$F_0 = 1; F_1 = 1$$
It doesn’t really matter.
However, the fibonacci-numbers tag wiki says unequivocally that $F_0 = 1$, while the excerpt says equally firmly that $F_0 = 0$. Should both wiki and excerpt be edited to be a little more open to variation?