Just as Alice and Bob are commonly associated with communication/cryptography lingo, we have Foo and Bar for programming. The origin for the word “Foo” goes back to a 1930s comic Smokey Stover by Bill Holman. But here’s where it gets interesting, Foo also links with the popular phrase/ graffiti Kilroy was here. The origins for Kilroy was here is disputed. But the Australian Equivalent was Foo was here.