The company you work for produces many reports for clients. All reports are sent via a secure email as a PDF attachment, and the reports all have a cover letter introducing the purpose of the document and a title page with your company's logo on it. You receive an email with a report. When you open it, the first page has the table of contents one it. You automatically know this report is not produced by your company. How do you know? 

 The report was in a PDF not a Word document like your company sends. 

The table of contents was incorrect. 

The report does not appear to use the correct template used by your company, which includes a cover letter and title page. 

The PDF report was not attached.