Admin Radar has evolved over the years, and thus Restrict Access To Auth Level is misleading now, as it is no longer the defining factor in who is allowed to use the radar. Those with permission can bypass the authlevel entirely. Detailed below...
Currently, it grants access in the following order.
1. Facepunch Developers always have access, regardless of how the config is set. This is my contribution to them for making the game for us, and to make their jobs slightly easier when they connect to a server and investigate issues.
2. Next up is Restrict Access To Steam64 IDs. If this list contains any entries, then only entries in this list will have access. All other means of access is denied.
3. Assuming #2 is an empty list, then those with permission (adminradar.allowed) will have access. Regardless of their authLevel. If they are not admin, then admin will be temporarily granted to them for access to ddraw. Use this at your own risk!
4. Lastly, Restrict Access To Auth Level any with an authLevel of this setting, or higher, will be granted access. By default, this includes moderators and admins.
By default: If you only want to use the authlevel, then never assign a permission. That's all there is to it.
I should rework this for clarity, but I simply do not want to burden any server owner with a new config file.