Please can anybody show me how to prevent other people convert pdf files to other formats? Such as Word, Excel, PowerPoint and so on.
Most of the time, when I was providing identity document as pdf format to organization, i would add watermark to it, such as " This [Name of the Documents] is dedicated for authenticating my identity in [organization]; I do not give My permission for any other use and also can not be copied " ......... in this case, does pdf have any features to delete its content within a period of time (such as 7 days, 15 days or 30 days. Can not be over 30 days)? Since I do not want organization to keep my Identity document forever, even if they promised to be deleted, I still do not trust them.