Create a Custom Content Type:

Go to your SharePoint Online site.

Click on Settings (gear icon) and select Site settings.

Under Web Designer Galleries, choose Site content types.

Create a new content type (e.g., “Product1 Classification”) based on the Document parent content type.

Add a custom column (e.g., “Classification”) to this content type.

Apply the Content Type to Document Libraries:

Navigate to the document library where the files are stored.

Click on Library settings.

Under General Settings, select Advanced settings.

Choose Yes for “Allow management of content types.”

Add your custom content type (“Product1 Classification”) to the library.

Manually Classify Files:

Upload or edit a file in the library.

In the file properties, select the Classification field and set it to “Product1.”

Permissions and Encryption:

Ensure that all authenticated users have at least View permissions on the library.

For encryption, SharePoint Online automatically encrypts files at rest using BitLocker disk-level encryption.

Files classified as “Product1” will be encrypted and accessible only to authorized users.