The Internet Engineering Task Force has published RFC 3092, an informational document that finally explains the etymology of the ubiquitous computing terms 'foo' and 'bar'. These metasyntactic variables have appeared in approximately 212 RFCs, or about 7% of all RFCs issued, starting with RFC 269. The document addresses a longstanding gap in technical documentation that has confused newcomers, especially non-native English speakers.

The RFC traces 'foo' back to the 1930s comic strip 'Smokey Stover' by Bill Holman, where the nonsense word appeared on license plates and in background text. The term gained popularity in the late 1930s, inspiring over 500 'Foo Clubs' and even an operable Foomobile vehicle. During World War II, British soldiers used 'FOO was here' graffiti, while American radar operators called mysterious radar traces 'foofighters' in 1944-45.

The document also explains the connection to 'bar', noting that the WWII-era Army slang acronym FUBAR ('Fucked Up Beyond All Repair') likely influenced the combination 'foobar'. The RFC provides a comprehensive historical account spanning comic strips, wartime slang, and the evolution of these terms into standard placeholders in programming examples and technical documentation. This clarification helps standardize understanding across the global technical community.