> For the complete documentation index, see [llms.txt](https://docs.fabricplan.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fabricplan.com/user-guide/5-top-down-allocation/5-3-locking-rules.md).
# 5.3 - Locking rules
### Lock cells directly
1. Select a cell, and then open the distribution menu.
2. Select **Lock this cell**.
3. Select **Lock all children** to lock descendant cells.
4. Verify that locked cells appear grayed out in the planning sheet.
5. Update a parent value to verify the effect on locked descendant cells.
6. Verify that unlocked descendant cells reflect the updated value while locked cells remain unchanged.
### Create locking rules
1. Open the **Model** ribbon.
2. Open the **Rules** dropdown.
3. Select **Locking rule**.
4. Enter a name for the locking rule.
5. Select measures for the locking rule by using the **Measures** dropdown.
6. Select the **Rule Type** field.
7. Select the checkbox to apply the rule to child rows and columns.
8. Open the **Rows selection** dropdown.
9. Select **All Rows** to apply the locking rule to all rows.
10. Select **Custom** to choose specific rows.
11. Select rows by using the checkboxes.
12. Select the **Filter** option to configure row filters.
13. Configure row filters by using the dropdown fields.
14. Select **Submit**.
15. Open the **Column Selection** dropdown.
16. Select **Open Period** to apply the rule to open-period columns.
17. Select **Period Range** to configure a date range.
18. Select a date range by using the calendar.
19. Select **Custom** to choose specific time periods.
20. Select time periods by using the checkboxes in the **Selection** tab.
21. Select the **Filter** option to configure column filters.
22. Select **Submit**.
23. Select **Create**.
### Manage locking rules
1. Open the **Rules** dropdown in the **Plan** ribbon.
2. Select **Manage rules**.
3. Manage locking rules by viewing, editing, duplicating, deleting, or disabling existing rules.
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://docs.fabricplan.com/user-guide/5-top-down-allocation/5-3-locking-rules.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.