How should SCI be marked in emails and electronic documents?

• A. Include classification and SCI indicators in the header, use encryption, and ensure only authorized recipients can access.
• B. Mark only the subject line with SCI.
• C. Do not mark; rely on trust.
• D. Mark as 'Confidential' only.

Answer: (A)

When handling SCI, you must clearly communicate both the overall classification and the SCI designation in the document’s header or top line, so anyone who handles it immediately understands its sensitivity. This explicit marking sets the expectation for how the material should be treated and who may access it. Pair that with strong encryption so the content remains confidential in transit and at rest, and enforce that only authorized recipients with the proper need-to-know can open it. SCI exists in compartments, so without precise indicators and protections, it’s easy for information to be exposed or mishandled. Marking only the subject line or using a generic label like Confidential doesn’t convey the specific SCI handling requirements, which is why those practices are insufficient.