If you have a variable called "TEST" that was first referenced using all upper case letters you cannot create additional variable names of "Test" and "test" since all variations of case represent the same variable. SAS stores the case of the variable that was first referenced and will continue to use that for display purposes.

If you want to change the case of the same variable name for example, from "TEST" to "test", it is best to use the DATASETS procedure with the MODIFY and RENAME statements.

Currently, you can also change the case of a variable using the RENAME= data set option, but this is valid only for input data sets, such as in a SET or MERGE statement, or as input to a procedure in the DATA= option. The RENAME= data set option for output data sets and the RENAME statement cannot be used to rename a variable simply to change the case.

In versions of SAS prior to SAS 9, internal processing for both input and output processing use case sensitive processing. With SAS 9 and beyond, output processing changed to use case insensitive processing for improved efficiency . Case insensitive means internally the case is not recognized so there is no difference between an upper case letter versus a lower case letter. With SAS 9, the current input processing uses case sensitive processing. This allows the RENAME= data set option to be used to rename the case of a variable for input data sets, but this could change in the future. It is best to use PROC DATASETS with the MODIFY and RENAME statements to change the case of a variable.

Operating System and Release Information