User blog comment:TheTobarMethod/A New View On ADC's IMO/@comment-6301771-20130211231754

AD caster is a metagame sub-class of AD carry. It is an AD focussed champion who carries the team. Difference is, casters rely more on abilities.

You are saying nothing new here, and are quite wrong on a number of points, most notably calling Vayne an AD caster. Obviously you've never seen her actually played. All she does is autoattack, and it RIPS through enemies.