Who do i have to contact in order to get the legal rights to put the superman sign on my letterman jacket?

Basically i want to put the superman sign on my jacket but the guy at the store said i have to get the ok from DC. However i do not know who to call or how to contact them. Or what i would ask. Someone please help|||They sell iron ons at like walmart what do you mean dc approval and don't expect anything good to come out of obama