I have added some users in Active Directory and have imported them to SharePoint. After this, I wrote code to get their Sid. For users who have a blank Sid, I tried to get their UserId.NameId. I had the following observations. Can anyone please explain this with reasons and valid reference links from MSDN or TechNet? I am really confused.
For the users whose login name starts with “i:0#.w|”, the Sid is empty, but have NameId.
For the users "Everyone","NT AUTHORITY\Authenticated Users" and "System Account"whose login names are "c:0<.s|true" ,"c:0!.s|windows" and "SHAREPOINT\System" respectively, both Sid and NameId are empty.
For the user "NT AUTHORITY\LOCAL SERVICE" and "NT AUTHORITY\SYSTEM", there is a proper Sid.
For the user "SharePoint App", Sid is empty, whereas NameId is in the format "app@sharepoint".
For domain users group, i.e whose user name is like "\domain users", Sid and NameId are both empty.
How does this behave with FBA?