What is the "prohibition" of Mr Fires that is not heard in Old Newgate?

When you go join the Dagger or Flint bee-hunting carousel, the introduction mentions that "Mr Iron's prohibition was not heard here". What is this talking about, it seems a bit out of Mr Evil Factory Bat's wheelhouse. Does he dabble in the bee trade too? Is Dagger or Flint some outlawed predecessor to Knife and Candle? I have no clue and would like to be clued in.