PSA: Queue as the role you're playing in TB
Back when they introduced the Icons, we got a lot of top-lane Marksmen, Mid-lane support, and the like because people who didn't play every role wanted every icon. That was okay because they would explain that in the lobby.
Now, it's no different. If your role doesn't match what you're going to build, say so.
If you're going to play Shen as a tank top, and your role says Assassin: Explain to the team that you're actually going to build Tank.
More importantly:
There are many mages who can be supports; however, IF YOU ARE GOING TO BUILD PURE MAGE, with no income items, wards, or supportive items of any kind, **SAY SO. **
Do not queue up as support just to find a spot quicker, then build the champion as if you were going into a solo lane (ie., starting doran's ring which pus you at a disadvantage. The build of a lying "mage" support is the same as if you were feeding in mid-lane. You'll be behind in gold.)