.rar (Roshal Archive), which requires software like WinRAR, 7-Zip, or The Unarchiver to extract. Naming Convention:
It may be a partitioned data set where "GP" stands for "Group Policy" or "General Purpose" data. Security Recommendation [KS] KS4 GP11.rar
Since .rar files can execute scripts or contain malware if sourced from untrusted third-party sites: .rar (Roshal Archive)