Comment by nemo

If you've learned even a little about the history of Rome then you'll quickly bump into SPQR, Mary Beard's recent popular, and very good book on the Romans it titled "SPQR", in the city of Rome you'll see SPQR used all over, in films when Romans are depicted, SPQR is always there. While not everyone will have a background where it's familiar, it's also not at all obscure. If you're not familiar with the Romans you won't know, but lots of people like to learn about the ancient past since it's really interesting to some types.