Microsoft Copilot Notebooks let you compose long-form content with AI assistance. When you pin specific sources in your notebook, Copilot prioritizes those documents when generating responses. This feature controls which files the AI reads first. Without source pinning, Copilot may pull information from any connected data source in an unpredictable order. This article explains how source pinning works, how retrieval order affects your outputs, and how to configure sources for consistent results.
Key Takeaways: Source Pinning and Retrieval Order in Copilot Notebooks
- Copilot Notebooks > Source pinning icon (thumbtack): Pinning a source forces Copilot to read that document first when generating responses.
- Copilot Notebooks > Sources panel > Drag to reorder: You can manually arrange unpinned sources to set a fallback retrieval order.
- Microsoft Graph data sources (SharePoint, OneDrive, Teams): Only files indexed by Microsoft Graph can be pinned; local or unsupported file types are ignored.
How Source Pinning Changes Copilot’s Reading Order
Copilot Notebooks use a retrieval system that searches across all connected Microsoft Graph data sources. Without pinning, Copilot retrieves information based on relevance scoring, recency, and user activity signals. This can produce varied results each time you ask a question about the same topic. Source pinning overrides this automatic ranking. When you pin a document, Copilot reads it first and treats its content as the primary context for the current notebook session. This is useful when you have a specific contract, policy document, or proposal that must be the basis for all AI-generated content in that notebook.
The retrieval order works in two tiers:
- Pinned sources: Read in the order you pinned them. The most recently pinned source is read first.
- Unpinned sources: Read after all pinned sources, in the order they appear in the Sources panel. You can drag to reorder them.
If you pin five documents and have ten unpinned documents, Copilot reads the pinned ones first, then the unpinned ones in the order shown. If the pinned sources contain conflicting information, Copilot uses the content from the most recently pinned source as authoritative for that session.
What Happens When No Sources Are Pinned
When no sources are pinned, Copilot uses the default retrieval order based on Microsoft Graph relevance scoring. This scoring considers factors such as how recently a file was modified, how often you access it, and how closely the file title matches your prompt. The order can change between sessions as these signals update. For consistent results in recurring work like weekly reports or client proposals, pin the relevant source files at the start of each session.
Steps to Pin and Reorder Sources in Copilot Notebooks
Open a Copilot Notebook in Microsoft 365 Copilot. The Sources panel is on the right side of the notebook interface. If you do not see it, click the Sources icon in the toolbar. Follow these steps to configure retrieval order.
- Open the Sources panel
In your Copilot Notebook, click the Sources icon in the upper right toolbar. The panel displays all available data sources connected to your Microsoft 365 tenant, including SharePoint sites, OneDrive folders, and Teams channels. - Locate the file you want to pin
Use the search bar at the top of the Sources panel to find a specific document. You can also scroll through the list of recent files or browse by source location. Only files indexed by Microsoft Graph appear here. Local files on your desktop or files in unsupported formats like .zip or .exe are not shown. - Pin the source file
Hover over the file name and click the thumbtack icon that appears. The icon changes to a filled thumbtack, and the file moves to the Pinned section at the top of the Sources panel. Repeat this step for each file you want to prioritize. - Reorder pinned sources
In the Pinned section, click and drag a file to a new position. The topmost pinned file is read first. If you want a specific document to be the primary source, drag it to the top of the Pinned list. - Reorder unpinned sources
Scroll to the All Sources section. Click and drag any unpinned file to change its position. This order applies only after all pinned sources have been read. You can also use the search bar to find and drag files from different data sources into the desired order. - Verify the retrieval order
Type a prompt in the notebook and review the response. The generated text should reflect the content from your pinned sources first. If the response still pulls from unpinned sources, check that the pinned files contain the relevant information. Copilot cannot read pinned sources that do not contain the data you are asking about.
Unpinning a Source
To remove a source from the pinned list, hover over the file in the Pinned section and click the filled thumbtack icon. The file returns to the All Sources list in its original position. Unpinning does not delete the file from your tenant or from the Sources panel.
Common Mistakes When Configuring Retrieval Order
Copilot Ignores Pinned Sources and Uses Other Data
If Copilot does not use your pinned sources, check that those files contain the specific information you are requesting. Pinning a file does not force Copilot to invent content that does not exist in the source. Also verify that the file is indexed by Microsoft Graph. Files stored in a local folder or in a third-party cloud service like Dropbox cannot be pinned. Move those files to SharePoint or OneDrive and wait for indexing to complete, which can take up to 15 minutes.
Pinned Sources Produce Conflicting Answers
When you pin multiple sources that contain contradictory data, Copilot uses the most recently pinned source as the tiebreaker. If you pin a 2022 policy document after a 2024 policy document, Copilot reads the 2024 document first and may use its content over the 2022 document. Reorder the pinned sources so the most authoritative document is at the top of the list.
Copilot Returns Generic Output Instead of Tenant-Specific Data
Generic responses often mean Copilot cannot find the requested information in any connected source. Ensure your pinned sources are accessible from your Microsoft 365 account. Check that the files are not restricted by sensitivity labels or sharing permissions. If a file is shared only with a specific group and you are not a member, Copilot cannot read it. Ask the file owner to grant you at least read access.
Copilot Notebooks Retrieval Options: Pinned vs Unpinned vs No Sources
| Item | Pinned Sources | Unpinned Sources | No Sources |
|---|---|---|---|
| Description | Manually selected files read first in pinned order | All connected files read after pinned sources in panel order | No files are connected; Copilot uses general knowledge |
| Use Case | Drafting a contract based on a specific template | Researching a topic across your entire tenant | Brainstorming ideas without data constraints |
| Consistency | High — same sources in same order each session | Medium — order can shift if you reorder the panel | Low — output varies based on general knowledge |
| Performance | Fast — Copilot reads fewer files first | Slower — Copilot scans all connected sources | Fastest — no file retrieval required |
| Data Freshness | Depends on the pinned file version | Uses latest indexed version of each file | N/A |
Pinned sources give you the most control over what Copilot reads and in what order. Use unpinned sources when you want a broad search across your tenant. Use no sources when you do not need file-specific answers.
Now you can pin sources in Copilot Notebooks to control which documents the AI reads first. Start by pinning your most critical file, then reorder additional sources as needed. For advanced control, combine source pinning with the Set context command to limit the notebook to specific SharePoint sites or folders. This gives you precise authority over every piece of data Copilot uses to generate responses.