An asset is Public if it contains either of the following:
The owner invited one or more users outside of your organization to collaborate on the asset.
The owner created a company-wide URL giving anyone in the company direct access to the asset.
Includes assets the owner has not shared. Also includes assets the owner has shared, but only with users within the company. These users have an email address in the enterprise domain name.
Shared via Custom URL
The owner created a custom link, vanity URL, or password-protected link for direct access to the asset and then shared this asset (directly or indirectly) using the link.
This option is for Box assets only and hidden if you are not using SaaS Security API to secure Box applications.