The Talmud, starting with the Mishnah(c. 220 CE) uses 'Reuven', 'Shimon', 'Levi' etc. being the names of the three eldest sons of Jacob and the corresponding tribes of Israel, as disputants in legal matters.
variable valve timing | Variable (programming) | Variable valve timing | Variable surface glycoprotein | variable star | variable (programming) | Variable-message sign | variable-message sign | Variable-length code | Variable-incidence wing | Variable Hawk | Variable Geometry | Variable geometry | Variable elimination | Variable data printing | Variable cost | Variable capacitor | Variable bitrate | Variable Assembly Language | variable | RR Lyrae variable | New Zealand's bush is variable in appearance, but generally the term connotates densely forested areas, like this one around Lake Gunn | metasyntactic variable | Local hidden variable theory | Limited dependent variable | Green's function for the three-variable Laplace equation | ''dependent'' or ''response'' variable | Cataclysmic variable star | American Association of Variable Star Observers |
Schwartz selected the world of The Flintstones for the examples in this book, giving rise to the somewhat frequent use of Fred and Barney as metasyntactic variables, rather than the classic foo and bar.