The VAR statement specifies three or four variables: the first variable contains an individual’s name, the second variable contains the name of the individual’s first parent, and the third variable contains the name of the individual’s second parent. An optional fourth variable assigns a known value to the covariance of the individual’s first and second parents in the current generation.
The first three variables in the VAR statement can be either numeric or character; however, only the first 12 characters of a character variable are recognized by the procedure. The fourth variable, if specified, must be numeric.
If you omit the VAR statement, then the procedure uses the first three unaddressed variables as the names of the individual and its parents. (Unaddressed variables are those that are not referenced in any other PROC INBREED statement.) If the input data set contains an unaddressed fourth variable, then it becomes the covariance variable.