What method of security classification guidance does an OCA us when heshe provides guidance in the form of a memorandum plan message document letter or an order?

An Original Classification Authority (OCA) uses the classification guidance established by Executive Order 13526 and related directives when providing security classification through memoranda, plans, messages, documents, letters, or orders. This guidance outlines the criteria for classifying information based on its potential damage to national security if disclosed. The OCA must ensure that the classification is appropriate, consistent with the established criteria, and that it includes a clear rationale for the classification decision.