What does the proofreader mark "____" indicate?

The proofreader mark that indicates "underline the text" is widely recognized in proofreading and editing practices. This mark signals to the editor or typesetter that the specific text should be emphasized by underlining, which is a common stylistic choice in various publications for titles, headings, or certain keywords. Understanding the context in which underlining is used is essential for maintaining clarity and emphasis that aligns with the intended message of the document.

Highlighting and italicization are separate techniques used for different purposes in written text. Strike-through usually denotes that text should be deleted, thus not aligning with the instruction to underline. Each of these marks serves a different purpose, reinforcing the importance of knowing the specific meanings to produce clear and professional documents.