The PowerShell script New-RoomMailbox has been updated, and release v1.2 has been published to GitHub and TechNet Gallery.
The script now creates a third mail-enabled security group to limit the users allowed to book the resource. The group is created (prepared) but not assigned to the room resource.
Additionally, the default language (locale) is configured. This prohibits the “Set locale” – dialogue when accessing the room mailbox using Outlook on the Web.
Read more here: https://www.granikos.eu/en/justcantgetenough/PostId/337/create-a-new-room-mailbox-with-security-groups.