What are the main four severity levels of signature in HIPS?

In Host Intrusion Prevention Systems (HIPS), the main four severity levels of signatures typically include:

1. Informational: Low-level events that provide data but do not indicate a threat.
2. Warning: Potential threats that may require investigation but are not immediately harmful.
3. Critical: High-risk events that indicate serious attacks or breaches that need immediate attention.
4. Fatal: Severe incidents that compromise system integrity, requiring urgent action to mitigate damage.