PDF User password
The User Password establishes viewing permission of the created PDF document. Without this password the document can be viewed by anyone. The user password cannot be set without the Owner Password. The maximum length of this password is 32 characters.
The PDF files created by the UNREGISTERED copy of SPLOT are for demonstration purposes only, so they can be only viewed. They cannot be modified, printed etc. So the UNREGISTERED copy of SPLOT uses internal owner password to always protect the created PDF file against printing, modifying and extracting.
Thus the User Password is the only security option which you can change with the UNREGISTERED copy of SPLOT.