The tabs of the docking control I use don't support hints (I bought the source so I can change that - I have to make it Unicode compliant as well anyway). So with all those funny icons and no room for explanatory text (there are still plenty people who use 1024x768), I decided to put those same tab icons on the Show - Windows menu.
Now, if you're wondering what a particular tab is for, you can compare its icon with those on the menu.
Even better: I added multiline hints to these menu items that explain how to use the functions they are associated with.