What constitutes a portion marking?

A portion marking refers specifically to the act of marking specific sections within a document that contain classified information. This practice is essential in clearly identifying which parts of a document are classified and at what level, thereby allowing readers to understand the sensitivity of the information without having to review the entire document.

When effective portion markings are applied, it promotes responsible handling of sensitive material, as it enables individuals to quickly ascertain what is classified and what can be shared or discussed further. Options that pertain to denoting the entire document, classification authority approval, or summarizing the classification of a document do not align with the definition of portion marking, as they either refer to broader concepts or administrative processes, rather than the specific marking of individual sections within the content.