Hi @Frederik-8475 ,
The GUID in the LoginName of the site user "Everyone except external users" typically signifies the tenant ID of the organization. However, there are instances where the GUID might differ from the tenant ID. This discrepancy can occur due to various reasons, such as changes in the tenant configuration or specific settings applied to the site.
The site user "Everyone except external users" is designed to provide access to all members of the tenant that owns the site, regardless of the GUID at the end of the LoginName. This means that even if the GUID differs, the access is still restricted to the members of the tenant.
Common types of login names in SharePoint online:
- Everyone -> c:0(.s|true
- Everyone except external users -> c:0-.f|rolemanager|spo-grid-all-users/<tenant_id>
- Group memebers -> c:0o.c|federateddirectoryclaimprovider|<group_guid>
- Group Owners -> c:0o.c|federateddirectoryclaimprovider|<group_guid>
- "Company Administrator" in Sharepoint Admin console -> c:0t.c|tenant|<UNKNOWN-GUID>
- An O365 user ->i:0#.f|membership|<USER-EMAIL>
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