This option serves as a default value for whether signature pages should be affixed to the document name after it is added to an agenda by Attach to New Agenda Item or Attach to Agenda Item. 

If selected, then the Signature page will be added automatically to the Agenda when an Administrator chooses Attach to New Agenda Item or Attach to Agenda Item within a meeting.

The signature page is appended to the end of the Document, and contains details about the approval steps taken to approve the document as well as any signature images that have been uploaded. Signature images can be managed within the user's profile (Users & Groups > User List). Signature images will only appear for Approvers only and not for Administrators and Delegates who approve on behalf of the approver.