It's my understanding there's no formal semantic distinction between single- or double-quotes as punctuation, and their usage is a typographic style choice. Your distinction does make sense in a couple of different ways, though. The one that immediately leaps to mind is the distinction between literal and interpreted strings in Perl, et al., though that's a bit of a niche association.

Also single-quotes are more commonly used for denoting dialogue, but that has more to do with historical practicalities of the publishing and printing industries than any kind of standard practise. The English language itself doesn't really seem to know what it's doing when it puts something in quotes, hence the dispute over whether trailing commas and full stops belong inside or outside quotations. One makes sense if you're marking up the text itself, while another makes sense if you're marking up what the text is describing.

I think I may adopt this usage.