Below are the insignia worn as a collar patches by the employees of Polish Post Office as defined by the Act of Polish Goverment from 27 Jun 1930. The Post Office uniform was brown with cut similar to the military. The cap was square "rogatywka" also similar to military with the "rusty-browm" cap band. Above the cap band there was a silver Polish Eagle and on the cap band the postal sign (trumpet). On the top part of the cap band there was a silver lace for employees paygrade XIV till XI (gold for paygrade X).
Images by MAGNUM, based on the original Goverment publication