Is _Yr2006_Patient_Data a valid data set name?

The data set name "Yr2006_Patient_Data" is valid in SAS because it adheres to the naming conventions set forth by the language. In SAS, valid data set names must start with a letter (A-Z, a-z) or an underscore (), can include letters, digits (0-9), or underscores, and must be no longer than 32 characters.

In this case, "_Yr2006_Patient_Data" begins with an underscore, which is permissible. It contains letters and underscores throughout its entirety, confirming that it meets all the necessary criteria for a valid SAS data set name. Therefore, the answer provided accurately reflects the validity of the data set name, confirming that it is indeed a valid choice.