Starting in SAS^® Version 7, all variables that are not explicitly assigned a label in the LABEL statement are assigned a null value for the label. Prior to SAS Version 7, unlabeled variables were assigned a label value of a blank.

This change was made in order to improve the establishment of variable attributes in the Program Data Vector (PDV) at compile time. For example, prior to SAS Version 7, if you want to override a variable's label with a blank using the ATTRIB statement or the LABEL statement, you must specify either the ATTRIB statement or the LABEL statement after the SET statement. If the ATTRIB statement or the LABEL statement is specified before the SET statement, the original label text is not overwritten.

As a result of this change, the ATTRIB statement or LABEL statement can now be used anywhere in the DATA step (for example, either before or after the SET statement) to override a variable's label with a blank.

Operating System and Release Information