The rule titled 'Unsuccessful Netbackup backups' is designed to identify and analyze failed backup attempts made by the NetBackup solution on various hosts. This rule utilizes a Splunk search query to extract logs related to backup processes from the system, specifically targeting logs that report error messages indicating that a backup failed. It aggregates the logs by computer name, capturing the latest timestamp of attempts and generating a tabular view containing the most recent failed backup times alongside the respective host names and error signature. Given its 'deprecated' status, this rule might not be actively maintained and users must consider adapting it for use with current technologies or alternate backup solutions if NetBackup is not their primary tool.