New documentation explains how the policy blocks federated sign-ins when the trusted realm and mapped user account have different root domains. It also documents the related Microsoft Graph beta APIs.
RetirementAction required The documentation now states that tenants created after January 5, 2026, cannot use custom CSS. After July 21, 2026, older tenants not already using it cannot configure it, and support for custom CSS layout and positioning properties is being retired.
RetirementAction required The documentation now covers custom CSS layout and positioning properties, and updates its publication date to August 18, 2026. It describes support for these properties as being retired under the Secure Future Initiative.
The documentation now identifies device-based X.509 authentication with the `x509` AMR value and explains that `x509` alone does not meet phishing-resistant MFA requirements. An additional authentication factor is required.
The reference now distinguishes `hwk` for multifactor CBA from `x509` for single-factor CBA, adds device-based X.509 authentication, and explains that `x509` alone does not indicate phishing-resistant MFA.
RetirementAction required The documentation now states that, after July 21, 2026, eligible tenants without existing custom CSS cannot configure it. It also expands the list of layout and positioning properties that will eventually be blocked and updates the inspection steps.
The deployment guide no longer states that Platform SSO for macOS uses hardware-backed storage by default. The Intune setup link remains unchanged.