For the dense input format, the ROW statement specifies a character variable in the problem data set that contains a name for each row of constraint coefficients, each row of objective coefficients and each variable describing row. If the ROW statement is omitted, the LP procedure looks for the default variable name, _ROW_. If there is no such variable in the problem data set, the procedure assigns the default name _OBS_ to each row, where specifies the observation number in the problem data set.

For the sparse input format, the ROW statement specifies the character variables in the problem data set that contain the names of the rows in the model. Rows in the model are one of the following types: constraints, objective functions, bounding rows, or variable describing rows. The ROW variables must be character variables. There must be the same number of ROW variables as variables specified in the COEF statement. If the ROW statement is omitted, the LP procedure looks for the default variable names having the prefix _ROW.