What Did I Dispel
Whenever you successfully dispel a buff or de-buff, the addon will display a link to the dispelled spell in your chat window. Clicking on this link will show you exactly what you dispelled. The addon also tracks all of your dispels, and you can display a list of them on demand. Right-clicking on a spell link will bring up a popup with a wowhead.com link to the spell.
For options, type /dispel help