Open a file command instead of hyperlink?

[mghia]

After exporting an .odt file with hyperlinks as a pdf I run into an issue with Acrobat reader security popups requiring confirmation before opening. They also have a checkbox to allow future PDFs to open but it doesn’t work and many report this.
The structure of the hyperlink created in LibreOffice is “file///…”

Below is a comment from an Adobe forum responding to somebody else who had this issue.
What is the “open a file command” ?
However there’s no instructions. Is open a file command something that is used in PDF creation or is it something I enter instead of creating a hyperlink in LO?
"You should not be using the file:/// domain for files that are located on the local computer. This will trigger a security warning because it is considered an attempt to access a file using an external link.
Instead, you should use an “Open a File” command, which points to this file. If it’s a PDF then no warnings will be shown when you click it (maybe only during the first time)."

I am using Win 10 and LO v7

[anon73440385]

What is the “open a file command”

You need to ask an expert of the PDF format definition but I’m quite sure that there is no other thing than a hyperlink to a file, which can be done in LibreOffice (and the whole advice sounds like using Adobe’s Java scripting in PDFs, which isn’t supported in LibreOffice at all - see Action types at Applying actions and scripts to PDFs).