Mila or Mimi'?

This can be possibly understood only by italians, but...

It is not the number 7 of Mila, neither the number 2 of Mimi', but it is maybe a beginning and a multiplication of the two numbers?
(Disclaimer, Mimi' wears a t-shirt with number 1 in some cases...)

Front and back of my first "real" volleyball t-shirt