Adding comments to doctype (similar to how system adds 'User Created', 'User Submitted' etc...)

I need to add audit trail comments just like how the system does. When I do add_comment, it appears different from the comment added by the system, and the user added comments can be deleted by the user as well. How can I add system comments n the audit trail to the doctype?

cur_frm.comments.insert_comment(comment_type, comment)

Comment Types should be in

    Email
    Chat
    Phone
    SMS 
    Created
    Submitted
    Cancelled
    Assigned
    Assignment Completed
    Comment
    Workflow
    Label
    Attachment
    Attachment Removed
1 Like

@saurabh6790 Thanks a lot.