Final answer:
Classification Level, Classification Authority, and Reason for Classification require all standard classification markings.
Step-by-step explanation:
Classification markings are important for properly identifying and handling classified materials in order to protect sensitive information. The types of classified materials that require all standard classification markings include:
- Classification Level: This indicates the level of sensitivity or secrecy of the material.
- Classification Authority: This identifies the authority that classified the material.
- Reason for Classification: This explains the basis or justification for classifying the material.
These three elements are essential for ensuring that the classified materials are properly identified, protected, and handled in accordance with established protocols.