The PRINT Procedure

ID Statement

Identifies observations by using the formatted values of the variables that you list instead of by using observation numbers.

Featured in: Controlling the Layout of a Report with Many Variables and Creating a Customized Layout with BY Groups and ID Variables

ID variable(s);

variable(s)

specifies one or more variables to print instead of the observation number at the beginning of each row of the report.

Restriction:	If the ID variables occupy so much space that no room remains on the line for at least one other variable, PROC PRINT writes a warning to the SAS log and does not treat all ID variables as ID variables.
Interaction:	If a variable in the ID statement also appears in the VAR statement, the output contains two columns for that variable.

Using the BY Statement with an ID Statement
PROC PRINT uses a special layout if all BY variables appear in the same order at the beginning of the ID statement. (See Creating a Customized Layout with BY Groups and ID Variables .)