Most labeling programs reach the same question once Copilot arrives: for our most sensitive label, should Copilot be able to summarize the content at all? Purview has three ways to say no. They don't stop in the same place, and one of them leaves the file open to Copilot Chat. Choose by where you need the line, not by whichever setting someone found first.
Control 1: the label setting that blocks content analysis
A sensitivity label can carry an advanced setting, BlockContentAnalysisServices, that stops Word, Excel, PowerPoint and Outlook from sending labeled content to Microsoft for analysis. Learn lists Microsoft 365 Copilot among the services that then don't work for that content in those apps. Since June, on newer Windows clients and all supported Mac and mobile versions, the setting covers all connected experiences that analyze content in Word, Excel and PowerPoint, not a subset (roadmap ID 561320, launched).
Learn also states the limit in an Important note: content with the label is excluded from Copilot in the named Office apps, but remains available to Copilot in other scenarios, such as Teams and Microsoft 365 Copilot Chat.
Two more costs. The setting exists only in PowerShell (Set-Label or New-Label); the Purview portal doesn't show it. And it switches off other things for that label, including automatic and recommended labeling, Outlook DLP policy tips, Translator and PowerPoint Designer on the older clients Learn lists. It's a privacy control for the Office apps. It isn't a Copilot boundary.
Control 2: encryption without the EXTRACT right
If a label applies encryption and doesn't grant the user the EXTRACT usage right (shown in the portal as "Copy and extract content"), Copilot won't summarize the content. Learn's Copilot considerations page says Copilot can still reference it with a link, so the user can open it outside Copilot. This works where the first control doesn't, because it travels with the file's protection rather than the app.
The exceptions are specific. Whoever applied the encryption is the Rights Management owner and always has EXTRACT, so content you encrypted yourself can always come back to you. Full control includes EXTRACT. And Learn warns that SharePoint IRM library settings apply usage rights only when a file is downloaded, so for files at rest it recommends labels that apply encryption without EXTRACT. Our labels post noted the VIEW and EXTRACT rule; this is where it decides the design.
Control 3: a DLP policy for Copilot
Learn's same page describes a third route. A Purview DLP policy can identify labeled files and emails, encrypted or not, and keep Copilot and agents from summarizing them, again leaving a reference link. It doesn't change the file's protection. It's a policy decision you can scope and adjust without re-encrypting anything.
Side by side
Block content analysis on the label. Where Copilot stops: Copilot in Word, Excel, PowerPoint, Outlook only. What else changes: Auto-labeling, policy tips and other connected experiences stop for that label. Set where: PowerShell.
Encryption without EXTRACT. Where Copilot stops: Copilot won't summarize; a link can still appear. What else changes: Users can't copy content out; the encryptor keeps full rights. Set where: Label encryption settings.
DLP policy for Copilot. Where Copilot stops: Copilot and agents won't summarize identified content. What else changes: Nothing about the file itself. Set where: Purview DLP.
Who decides
The records owner and the security owner decide, label by label, whether Copilot may summarize content that carries it, and which control enforces the answer. The compliance administrator configures it and tests it in each place people actually use Copilot: inside Word, in Copilot Chat and in Teams. Label owners accept the side effects in writing, especially if auto-labeling stops for a label you meant to apply automatically. If you've just turned on default library labels for existing files, check which of those labels these settings sit on.
Copilot respects labels. It respects only the parts of them you actually set.
