I don't know much about these platforms, and so I beg your pardon if what I write seems naive, but I do recognize the need for support for older versions. I use them myself on older HW, and I would really like to have dedicated areas specialized on old versions (and, too, dedicated repositories for them, with older versions of OS as well as SW versions).
So wouldn't it be fine to have either a new section or a new platform for these, and optionally a way to move questions there, accordingly? This way, they wouldn't "clutter" this platform, but nevertheless, satisfy the needs of those who have new questions about old versions.
This way, whenever a question appears that obviously concerns an older version, it can be moved to the dedicated "legacy" area and doesn't disturb anymore.
Perhaps something similar already exists and I don't know about it? In this case, I'd be grateful for the relevant information.
