The available managed rulesets are:
Proactive false positive detection for new rules
When Cloudflare creates a new managed rule, we check the rule impact against the traffic of Business and Enterprise zones while the rule is not blocking traffic yet.
If a is detected, we proactively reach out to the affected customers and help them make configuration changes (for example, to lower the sensitivity level of the new rule) before the rule starts mitigating traffic. This prevents the new rule from causing service disruptions and outages to your Internet properties.