Annotation is how a PDF becomes a conversation: you highlight the clause, underline the requirement, strike the passage that has to go, and pin a note asking why. The Rixoffice PDF Editor covers the full markup vocabulary — highlight, underline, strikeout, sticky notes, comment notes, rectangles, ellipses, arrows and ink — with markup colors that keep different reviewers distinguishable. Annotations follow the standard PDF model, so everything you add is visible in Acrobat, browsers and any compliant reader.
Text markup: highlight, underline, strikeout
- Open the PDF and select the highlight tool.
- Drag across the passage; the highlight lands on the text.
- Switch to underline or strikeout for the other two messages.
- Pick a markup color from the palette — keep one color per reviewer or per topic.
- Save; the markup writes into the file.
The three text tools carry three distinct meanings in review culture: highlight means *look here*, underline means *this matters*, strikeout means *delete this*. Keeping the meanings consistent across a document set is what makes markup readable at speed.
Sticky notes and comment notes
Two note types, two jobs:
- Sticky note — an icon pinned to a point on the page. Click it to open the text pop-up. Use it for standalone observations: a question about the page, a reminder, a decision.
- Comment note — attached to markup. Select a highlight or shape and add its comment, so the note and the mark travel together. A struck-out sentence with the comment "superseded by section 4.2" explains itself.
The pairing rule: if feedback refers to specific text or an area, attach it to markup rather than pinning a sticky note nearby — the reader sees the note exactly where the issue is.
Shapes and ink for visual markup
When the issue is an area rather than a passage:
| Tool | Draws | Typical use |
|---|---|---|
| Rectangle | Boxed region | Flag a chart area, box a form field |
| Ellipse | Circled region | Circle the data point in question |
| Arrow | Directed pointer | Point from note to subject |
| Ink | Freehand | Sketch, scribble, sign-off gestures |
Shapes take the same markup colors as text tools, so a red rectangle and a red highlight read as one reviewer's thread. The dedicated draw tools guide covers freehand drawing in more depth, including continuous sketching across pages.
A review pass that finishes
Markup fails when it sprawls. A pass that lands:
- Read once without annotating — know the document before marking it.
- Markup in one color per topic (content red, formatting blue, questions yellow).
- Attach comment notes to markup instead of scattering sticky notes.
- Use strikeout for deletions so the author sees exactly what goes.
- Save and send; the recipient sees your markup in their reader, unchanged.
If the review ends in edits rather than feedback, switch tools: edit text in place, or have the AI assistant apply the markup as edits — it can read the pages and the markup, then make the changes.
What annotations are good for — and not
Annotations excel at communication and review. They do not change the document's content: a struck-out sentence is still there under the strike. When the deliverable is a corrected PDF, the sequence is annotate first, then edit — and if the receiving side only needs approval, a stamp with name and date is more official than any highlight.
What to explore next
- Draw tools for freehand and structured drawing beyond markup.
- Edit text in a PDF to turn feedback into fixes.
- AI assistant for markup-aware editing at scale.