My daily workflow includes emacs org mode files for each project I’m working on. I often link to files, programs, etc. from these org mode files. I tried linking to a MS Excel spreadsheet using my usual
file:/path/to/file.xlsx
link. However, since the xlsx file is really a zip file, emacs opened a dired buffer revealing the contents, rather than opening it in Excel.
After a bit of googling, I found a message from the org mode mailing list about linking to Excel and Word documents from org mode and discovered the file+sys link type. This, per the org mode External Links manual, will “open via OS, like double-click”, which is exactly what I want. Good reminder for myself: when all else fails, RTFM.