Choose **Save Comparison** after reviewing the result. Select the output that
matches how the recipient will use it.
Choose a separate output filename for redlines, Track Changes, merged documents,
packages, and comparison reports. These saves cannot replace the Original or
Modified source document.
RTF output is prepared before replacing an existing destination. If writing or
replacement fails, the existing file is preserved. Close any application locking
the destination, or choose another output location, then retry.
## Output formats
| Output | Use it when |
| --- | --- |
| Visual redline: DOCX, PDF or RTF | Someone needs to read marked-up changes. |
| Track Changes RTF | The receiving application needs revision marks. |
| `.dyd` package | You want to reopen or transfer the comparison with its packaged content. |
| Difference list: JSON | You need a list of changes with their kind, zone and section. Select **Also save the diff list as JSON** under **Redline Report**. |
| Merged document: DOCX, PDF or RTF | You want a document incorporating selected accepted changes; **Merged Redline** requires at least one accepted difference. |
| Comparison report | You need a summary of the comparison and its settings, optionally with a detailed table. |
The save dialog groups these choices under **Redline**, **Merged Redline**, and
**Redline Report**. The JSON companion is saved beside the report as
`_difflist.json`. When save confirmations are enabled, the confirmation
lists both files after they have been written.
Consecutive changes of the same kind across line breaks share one revision-list,
report and JSON entry. The actual redline document keeps its line breaks.
## Choose a document format
For a visual redline or merged document, the format selector offers **DOCX**
(the default), **PDF**, and **RTF**. RTF saves directly. DOCX uses the selected
SDK or Microsoft Word conversion mode; Word mode requires Word desktop.
PDF export uses Inkwell and requires its configured PDF workflow.
**Track Changes** in Save Diff produces RTF; the document-format selector is
hidden for that choice. A `.dyd` comparison package and a Redline Report use
their own output choices. PDF preserves a review view, not editable Word
revision marks. Check converted output in the receiving application.
## Keyboard navigation
In **Save Diff**, focus starts on the selected **Select Save Folder** option.
Press **Tab** to reach the tabs and the current tab's controls, followed by
**Cancel**, the format combobox (initially **DOCX**), and **Save**. Use the arrow
keys to change folders or tabs, and **Shift+Tab** to move backwards. Hidden or
disabled controls are skipped. If no save folders are configured, focus starts
on the tabs.
## Save a useful record
1. Choose a filename that identifies the original and revised versions.
2. Save to a location where you have write permission.
3. Keep the result separate from the original source files.
4. Open the saved file and check that it contains the result you intended.
A difference list is not a replacement for the complete document context. A
merged document and a redline also serve different purposes: keep both if you
need a final text and a record of the changes reviewed.
## Sharing a `.dyd` package
The recipient needs a compatible MarginDiff Documents version to reopen the package.
Documents packages use `.dyd`. The old `.diffy` extension is not supported.
Before sharing, check [what saved comparisons can contain](/docs/privacy/#saved-comparisons-can-contain-sensitive-content).
## Email attachment filenames
In **Email Comparison**, the Original, Modified, Redline and Track Changes
filename fields are read-only. Select **Edit...** beside a filename to change
it, then choose **OK**. **Cancel** keeps the existing filename.
Email Comparison opens with focus on **ZIP**. Press **Tab** to move to
**Cancel**, then **Open Outlook**.
## Print changed pages
In **File > Print**, leave **Print only diff pages** checked to print the pages containing changes. A page range chosen in the printer dialog further limits that selection. If the range contains no changed pages, choose another range or clear the checkbox.
Selected changed pages are sent as one print job, including when they are not consecutive. With **Inkwell PDF Printer**, choose a PDF filename to save them together in one PDF. With **Adobe PDF**, the same selection is sent as one print job; Adobe handles the PDF destination through its own printer settings or save dialog. Clear **Print only diff pages** to print all pages in the chosen range.