Is _Yr2006_Patient_Data a valid libref in SAS?

In SAS, a libref (library reference) must conform to specific naming conventions. A valid libref must begin with a letter or underscore and can be followed by letters, numbers, or underscores. It is also case-insensitive and should not exceed eight characters in length.

The name _Yr2006_Patient_Data violates these rules. Specifically, it begins with an underscore and contains more than eight characters. While the first character rule allows for starting with an underscore, subsequent characters must follow the naming conventions without exceeding the length limit. Therefore, _Yr2006_Patient_Data does not qualify as a valid libref in SAS.

Understanding the characteristics of valid librefs is essential for effective programming in SAS, as any invalid libref will result in errors when attempting to refer to or access the associated library.