Thanks again, for a very helpful response (also yvonnezed). The file:// protocol was mainly for testing, because I didn’t know tinyurl could be used for similar purposes, but could be of some use even if I value security.
Now, if I try file:// in Safari (on my Mac) pointing to a local file that file is at least revealed in Finder or even opened directly in Safari if it’s a pdf.
My main reason for dealing with these kinds of links and URL schemes is not for use in Google docs or Word but for an “Agenda” workflow integrating Drafts, OmniOutliner, Alfred, Keyboard Maestro and Hazel to some extent, which I covered briefly in another post Questions/Suggestions for Drafts for Mac Beta - Drafts for Mac - Drafts Community.
Happy New Year