User Configuration > Administrative Templates > Microsoft Outlook 2016 > Account Settings > SharePoint Lists
User
HKCU\software\policies\microsoft\office\common\offline\options
You can use this setting to define a custom label for the SharePoint Lists PST and most other places where the term "SharePoint" is used in Outlook. (Setting this value replaces the word "SharePoint" in Outlook strings with the value you specify.) A custom label might be particularly useful when deploying a third-party server that supports the same Microsoft SharePoint Foundation Web services Outlook uses for synchronization.