Add new param DisableClassicPageBaselineSecurityMode for Set-SPOSite PowerShell cmdlets

[libihan]

Add new param DisableClassicPageBaselineSecurityMode for Set-SPOSite PowerShell cmdlets

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.

[learn-build-service-prod]

Learn Build status updates of commit d2984b8:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOSite.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[libihan]

@microsoft-github-policy-service agree company="Microsoft"

[github-actions]

@xiaojhua-work
You've been added as a reviewer to this pull request because you're listed as a Content Lead for the product area or feature covered by one or more articles in this PR.

Before this PR can be merged, a Content Lead needs to add the Sign off label to it. Only one of the listed reviewers needs to add the Sign off label. Before you sign off a PR, confirm the following:

• Article content has been checked for technical accuracy.
• There are no errors or warnings in build validation.
• There are no severity 1 or 2 PoliCheck issues.
• All articles have a minimum Acrolinx score of 80.
• All required PR checks at the bottom of the PR are passing.

After you've confirmed the above, do the following to sign off:

1. Select the gear next to Labels.
2. Select Sign off from the label list.
3. Click away from the label list.

After you've signed off, our operations (PubOps) team will review the PR for issues that may impact formatting and the customer experience. If any changes are needed, they will return
the PR to the submitter with required changes. After they've completed those changes, you need to sign off again.

When the PR passes PubOps review, they'll merge the PR. If the PR is merged into the main branch, changes will go live within the next couple hours.

If you think you were incorrectly added as a reviewer, have questions about this process, or need help signing off on this PR, post a message to https://aka.ms/tcphelp.

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.

[learn-build-service-prod]

Learn Build status updates of commit d2984b8:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOSite.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.

[learn-build-service-prod]

Learn Build status updates of commit d2984b8:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOSite.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.

[learn-build-service-prod]

Learn Build status updates of commit fe5304f:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOSite.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[samkabue]

Need to confirm this prop name... #Closed

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.

[learn-build-service-prod]

Learn Build status updates of commit 9025ec6:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOSite.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[learn-build-service-prod]

PoliCheck Scan Report

The following report lists PoliCheck issues in PR files. Before you merge the PR, you must fix all severity-1 and severity-2 issues. The AI Review Details column lists suggestions for either removing or replacing the terms. If you find a false positive result, mention it in a PR comment and include this text: #policheck-false-positive. This feedback helps reduce false positives in future scans.

✅ No issues found

More information about PoliCheck

Information: PoliCheck | Severity Guidance | Term
For any questions: Try searching the learn.microsoft.com contributor guides or post your question in the Learn support channel.

[libihan]

Need to confirm this prop name...

Updated with DisableClassicPageBaselineSecurityMode

[learn-build-service-prod]

Learn Build status updates of commit 6ceeee2:

✅ Validation status: passed

File	Status	Preview URL	Details
sharepoint/sharepoint-ps/Microsoft.Online.SharePoint.PowerShell/Set-SPOSite.md	✅Succeeded	View (sharepoint-ps)

For more details, please refer to the build report.

[samkabue]

enabled at the tenant level

baseline security mode is enabled at the tenant level.

@libihan so is there an equivalent tenant-level property that can be set to $true | $false?

[libihan]

@samkabue Yes, there is a tenant-level property — not supported in the PowerShell cmdlets, but will be available to tenants in CY26H1 through the Microsoft Admin Center (market name: Baseline security mode – Block creation and editing of classic pages in SharePoint sites).

We added this site-level opt-out early to support MSIT in January.

[samkabue]

@libihan I'd suggest you guys also update the documentation for the tenant-level one, then reference it from here at that time. for now, this current PR is good to go.

[samkabue]