Older C compilers would truncate a variable name if it was too long, so VeryLongGlobalConstantInsideALibraryInSeconds might accidentally collide with VeryLongGlobalConstantInsideALibraryInMinutes.
Legend says that they used to do it after a single letter with Dennis declaring “26 variables ought to be enough for anyone”.
Older C compilers would truncate a variable name if it was too long, so
VeryLongGlobalConstantInsideALibraryInSecondsmight accidentally collide withVeryLongGlobalConstantInsideALibraryInMinutes.Legend says that they used to do it after a single letter with Dennis declaring “26 variables ought to be enough for anyone”.