Saving File to Open in Different Versions

Is there a way by which you can save out a Rhino file so that it can automatically be opened in the appropriate version of Rhino? Example, I save a file out as a Rhino 8 file and it will open into Rhino 8, but I could also save the same file out to Rhino 6 and it would be recognized to open in Rhino 6 without additional prompting on my part.

Hello- not that I know of - it’s up to Windows what open a given file format by default - you can change that but as far as I know only one at a time. (i.e. all 3dm files are equal, to Windows)

-Pascal

Pascal is right.
Windows “File association” to a specific application is determined by the most recently installed version of that application.

https://docs.revenera.com/installshield22helplib/helplibrary/FileAssociations.htm

In a future version of Rhino, could you possibly add some marker to the extension to help indicate version of rhino? So instead of just 3dm, it’s 3dm8 for R8, 3dm9 for R9, etc?