The meaning of a OSTtoPSTAPP Protecter PDF file is to protect PDF files. A protected PDF file is that either has permissions or open restrictions. In short PDF file is encrypted. If your PDF file has permission password protection then you would not need a password to open and view it but if it has an open password restriction then you need its password to unlock and view it. It is a modern tool to protect your PDF file by locking it with a very unique password. It protects your PDF file from copying, editing, or printing without your permission. It supports bulk PDF files which means it safe your time. Portable Documents Format Protector utility that has been tested for quality.