What is a portion marking?

A portion marking refers to a notation used to indicate the classification level of specific sections within a document. This system allows readers and users to understand the sensitivity of information contained in different parts of the document without needing to assess the classification of the entire document. By using portion markings, individuals can quickly identify which sections require protection and the specific classification levels that apply to those sections, such as Confidential, Secret, or Top Secret. This method enhances information management and security by providing clearer guidance on handling the classified material within the document.

The other options represent different concepts related to document handling but do not accurately describe what a portion marking is. For example, tracking document revisions pertains to keeping records of changes made to documents, while designating whole documents as classified touches on different classification levels that apply to complete files rather than specific sections. Lastly, labeling storage locations involves indicating where classified materials are kept, not how the information within those materials is classified.