Is the following TRUE or FALSE for Salesforce? (See description)

Hi Tanu,

Yes, It is  true by modify all data permission user must be able to delete.

• To delete a note or attachment, you must be the owner of the note or attachment or an administrator with the “Modify all Data” permission. Note ownership is determined by the owner field. Attachment ownership is determined by the created by field.
• Record owners (except Portal users) can delete attachments on records.
• Notes and attachments marked as private via the Private checkbox are accessible only to the person who attached them and administrators. For administrators to view private notes and attachments, they need the “View All Data” permission; to edit or delete them, they need the “Modify All Data” permission.

Hope this helps you.

Thanks