Mark a single passage
Upload a PDF and enter Edit mode. Choose Marker, select a color and adjust Thickness. Drag across a short phrase. On a meeting agenda, mark the revised time rather than the whole paragraph. Zoom in if a stroke touches the line above or below.
Give the highlight a meaning
Choose a consistent convention, such as yellow for items to discuss. Add a nearby Text note when the reason is not obvious: Confirm the deadline is more useful than an unexplained mark. Keep highlights clear of signatures, figures and stamps so the original stays readable.
Inspect contrast after export
Save and download, then inspect the page in another reader. A stroke over a dark scan can reduce legibility; adjust the color or thickness in your draft and export again. Highlights do not provide redaction. Anyone receiving the PDF may still read or extract the material under a mark.