Overview
The DISCO Native Spreadsheet Viewer precisely renders Microsoft Excel, CSV, and TSV files without converting them to TIFF or PDF. It works directly on the document's native XML structure, allowing legal teams to perform detailed, cell-level redactions while preserving workbook functionality through logic flattening and formula sanitization. This process identifies and removes sensitive data—including hidden sheets, pivot caches, and legacy notes—ensuring secure, redacted native workbooks that meet strict ESI standards.
This feature is in Run.
Redacting in Spreadsheet Viewer
To redact information in a spreadsheet or perform Excel redactions in the DISCO Spreadsheet Viewer:
- Start redaction mode by clicking Add Redaction / Edit Redaction in the left hand panel
- In the primary Ad Hoc document viewer, open the REDACTIONS section, or
- In the document viewers for Review Stage Batches or for Quality Control, look for the Add Redaction button
Adding redaction in primary Document Viewer
Adding redaction in Review Stage Batch Viewer
Adding redaction in Quality Control Document Viewer
2. Select the cells or images to redact, then click the Redact button or press R. The button updates to reflect your selection (e.g., Redact B42, Redact columns C-D, Redact E14:G23, or Redact entire sheet).
Like Microsoft Excel, you can select and redact cells by:
Clicking individual cells
Clicking a row or column heading to redact the entire row or column
Clicking and dragging your cursor over cells, rows, or columns
Using Shift + arrow keys
Using Shift + left click
Using Ctrl + left click (Command + left click on Mac)
Clicking the top-left corner or pressing Ctrl + A (Command + A on Mac) to redact the entire sheet. Note: Redacting a sheet also redacts all charts and images.
Selecting cells in various ways
Selecting an image
3. Each time you redact, a dialog box appears allowing you to:
Choose the redaction reason
Choose the redaction color
Delete the redaction
Redacted cells display the selected color with the redaction reason (if any) in the upper-left corner in the Spreadsheet Viewer. When produced, the document shows redacted cells with the reason (if any). The dialog box defaults to the reason and color chosen in the previous redaction.
Hidden content
Click the eye icon at the top right to toggle hidden content. Hidden sheets, columns, and rows always appear in redaction mode.
Hidden sheets, columns, and rows are always shown while redacting
You can toggle floating charts and images on or off while redacting. Redacting a chart or image does not automatically redact the cell content beneath it. To ensure no content is missed, toggle off floating charts and images to check underlying cells for content that requires redaction.
Toggle off the floating charts/images to check if the cells underneath have any content that needs to be redacted
Comments and Notes Redactions
Comments and notes in an Excel document are both considered comments and can be redacted in the Spreadsheet Viewer. Redactions apply to the entire comment thread but do not affect the cell content where the comment or note appears.
Redacting threaded comment and note
Workbook and Worksheet Redactions
To redact a workbook, sheet, or sheet name, click the down arrow next to the sheet names and select the option from the menu.
Redacting the entire workbook applies the same redaction color and reason to all worksheets and their names.
Redacting the entire workbook
Worksheets and worksheet names can be redacted individually or as a group.
Redacting single worksheet and sheet name
You can choose to react a group of sheets or sheet names, or choose to redact all but one sheet or sheet name.
Redacting all other sheets and all other sheet names
Editing Redactions
You can edit a redaction by clicking on the pencil icon and changing the reason and/or color.
Editing redaction name and color
Deleting redactions
Delete a redaction by clicking the X icon at its top-right corner or selecting “Delete redaction” in its edit popover.
Un-redacting
To un-redact part of a redaction:
Enter redaction mode by clicking "Edit Redactions"
Select cells within the existing redaction to un-redact. The redaction button reflects your selection (e.g., Un-redact A4, Un-redact A4:B5).
Press R or click the button to un-redact. The original redaction splits into multiple redactions, keeping unselected parts redacted.
Saving Redactions
After redacting, click Save to apply changes, including new, updated, or deleted redactions. In spreadsheets with multiple sheets, you can redact across sheets without saving each time you switch.
Jumping Between Redactions
You can use the Jumper in the upper right corner to easily find redactions made across a workbook.
Jumping between redactions
Document Audit History
The Document Audit History keeps a log of all the redaction changes that you make on a document.
Document Audit History
Redacting in PDF View
You can continue redacting spreadsheets in the PDF Viewer. Note that:
Redactions made in one view can only be viewed and edited there.
Before redacting in the Spreadsheet Viewer, delete redactions made in the PDF Viewer.
Before redacting in the PDF Viewer, delete redactions made in the Spreadsheet Viewer.
You cannot add or edit redactions in the PDF Viewer if redactions exist in the Spreadsheet Viewer. You will be prompted to edit redactions in the Spreadsheet Viewer.
You cannot add or edit redactions in the Spreadsheet Viewer if redactions exist in the PDF Viewer. You will be prompted to edit redactions in the PDF Viewer.
Searching
Use the new search syntax to find documents with redactions.
hasRedaction(onPDFViewer) - Returns documents with redactions in the PDF Viewer
hasRedaction(onSpreadsheetViewer) - Returns documents with redactions in the Spreadsheet Viewer.
Searching for redactions made on documents in the Spreadsheet Viewer
Producing Redacted Excel Documents
Redacted Excel documents can be produced as a PDF image or a native .XLSX file. If redactions were applied in the Spreadsheet Viewer, you can produce either format. If applied in the PDF Viewer, only PDF image files can be produced.
Choose to produce redacted Excels as either "Redacted images" or "Redacted .XLSX files"
Produce as Redacted images
If you select "Redacted images" for production, Excel documents will be produced in the chosen image format (PDF, TIFF, JPG).
A note about overflow text:
Spreadsheet cells can have their content set to overflow, wrap text, or shrink text to fit. Consider a scenario where a cell (A3) is set to overflow, and the adjacent cell (B3) is redacted. When this spreadsheet is saved as an image, part of the non-redacted cell's (A3) content may be covered by the redaction area. Although the covered content is invisible, it remains part of the image. If you choose PDF as the output format, the covered content can be searched and copied from the PDF. It also appears in the OCR .txt file included in the production .ZIP file.
Produce as .XLSX Files
If you select "Redacted .XLSX files" for your production, those Excel documents will be produced as native Excel files.
The redaction reason and color appear in the produced .XLSX file as shown in the Spreadsheet Viewer. Below are examples of various redaction scenarios in both the .XLSX file and DISCO's Spreadsheet Viewer.
Redacted sheet name
A redacted sheet name replaces with {Redacted, <redaction reason>}.
Redacted cells, columns, rows
Each redacted cell shows all redaction reasons.
If a cell has multiple redactions, all reasons appear on the cell, separated by semicolons.
Example of a document with sheet name redaction and overlapping redactions
Full Sheet Redactions
Full sheet redactions apply redaction color to every cell, with the reason in the top-left cell.
All charts, graphs, and comments in the sheet will be redacted, but the sheet name remains visible.
Example of full sheet redaction
Formula Redactions
A cell with a formula referencing a redacted cell shows the value but not the formula.
Redacting a formula in one cell redacts it in all cells referencing that formula.
Example of a cell value calculated from the sum of redacted cells
Comment Redactions
Redact a cell and its comment separately.
Redacting only a cell leaves its comment visible.
Redacting only a cell's comment leaves the cell visible.
Example of redacting a comment.
Technical FAQ
Core Mechanics & Logic Flattening
Q: How does DISCO prevent redacted data from being "reverse-engineered" via formulas in a native production?
A: DISCO uses a "Logic Flattening" protocol. When a cell used in a formula or the formula cell itself is redacted, the system removes the formula from the XML. In the produced .XLSX, the cell shows its last calculated static value as text or a number, but the calculation logic is removed. This stops recipients from using Excel’s "Trace Precedents" or auditing tools to reveal redacted inputs.
Q: What if a formula in Cell A1 references Cell B1, and I only redact the formula in A1?
A: Redacting one formula automatically redacts all formulas that reference it. This "cascading sanitation" ensures proprietary calculations or sensitive logic do not leak through dependencies elsewhere in the workbook.
Q: How does DISCO handle sheet name conflicts when multiple tabs are redacted?
A: Excel requires unique sheet names with a 31-character limit. If multiple sheets are redacted for the same reason, DISCO appends a unique enumerator (e.g., {Redacted, Confidential} (1)). The system ensures the reason and enumerator do not exceed 31 characters or contain illegal characters (e.g., :, \, /).
Hidden Data & Security Risks
Q: How does the viewer handle "Very Hidden" sheets and legacy "Print Areas"?
A: DISCO overrides Excel’s visibility flags. "Very Hidden" sheets—invisible in Excel’s UI—are unhidden in the Viewer and marked with an indicator. DISCO also ignores "Print Area" metadata during rendering, ensuring data hidden by print range restrictions is fully visible for review and redaction.
Q: Does redacting a cell automatically redact its Comment or Note?
A: No. Cell values, legacy Notes, and modern Threaded Comments are separate data objects. Redacting a cell does not redact its comment. Reviewers must explicitly select the cell and toggle "Redact Comment" in the redaction dialog. Otherwise, sensitive data remains visible in the Comments pane or as hover-text in the produced native file.
Q: How is "Invisible Text" surfaced for review?
A: DISCO detects text matching its background color or set to 0% opacity. When "Show Hidden Content" (eye icon) is active, these cells show an icon overlay. The raw value appears in the formula bar, allowing precise redaction of otherwise invisible data.
Q: Can I redact a Pivot Table without risking data leaks in the Pivot Cache?
A: Redacting Pivot Table cells only hides the visual data. It does not sanitize the "Pivot Cache"—the background data stored in the file. To fully protect data, redact the entire source data sheet or produce the document as a redacted image to ensure no background cache remains.
Mass Redactions & Conflict Resolution
Q: What priority logic applies when a "Mass Redaction" term overlaps with a "Pattern" (RegEx)?
A: DISCO prioritizes specific terms and phrases over general patterns. If a term-based rule and a RegEx rule target the same cell for different reasons, the term-based reason appears in the visual overlay and production placeholder.
Q: If I manually modify a redaction applied via a Mass Action job, what changes?
A: Any manual edit (color, reason, or size) changes the redaction’s origin from "Mass" to "Manual." This security feature excludes manual redactions from "Mass Action Rollbacks," preventing accidental exposure of data verified by a human reviewer.
Q: What are the maximum scale limits for native spreadsheet redactions?
A: There is a 500-redaction limit per document (manual and mass combined). For large spreadsheets, the native viewer has a JSON rendering limit near 40MB. If exceeded, the system may prompt the user to download the file or review it in PDF/Text view.
Production & Quality Control
Q: Can I produce a redacted CSV or TSV file?
A: No. DISCO supports reviewing and redacting CSV/TSV files in a grid, but they cannot be produced in their original format. To preserve redaction placeholders and data integrity, redacted CSVs must be produced as redacted native .XLSX or redacted PDF images.
Q: How is "Overflow Text" handled during image (PDF) productions?
A: If a cell’s text "overflows" into an adjacent redacted cell, the redaction box on the PDF may cover the text, but the Extracted Text/OCR may still include the full string. For absolute security, redact the source cell of the overflow or produce as native .XLSX, where data is removed from the XML.
Q: How can I search for redaction "Collisions" before a production deadline?
A: Run the search syntax hasRedaction(onPDFViewer) AND hasRedaction(onSpreadsheetViewer). DISCO treats these as separate markup layers. To produce a redacted native file, remove existing PDF redactions, as the system defaults to image production if PDF markups exist.