Did the Australian solders of ww2 wear their service number on their uniform?

yes they dO wear unifOrm....every where yuh qO some kiidss still where unifOrm

The numbers allow officials and spectators to recognise or identify a player from a distance, or when it is otherwise impossible to distinguish players from one another by other means.

There is no requirement in the FIFA Law of the Game for the jerseys to have numbers on them. However, most leagues do implement requirements that players be uniquely identifiable by their jersey....

Mickey Mantle wore uniform number 6 in his first year then wore the number 7 for the rest of his career.

2nd Baseman of the New York Yankees Robinson Cano.