Add posibility to tag tasks

Sometimes, I have to give my dock a moment's look to figure out what's what. It would be nice to have a feature whereby I can select to display task labels, so that slow folk like me can see what's what, and don't have to remember where things are on the dock to tell windows with the same icon apart.

Because this is not easy to explain properly, I have taken the liberty of mocking up what this might look like, in the attached image, so that the gist of what I'm asking for is clear. Perhaps in my image they are too far apart, but that's by-the-by; it represents what I'm getting at.