Push "insert" and you'll see the last person that has whispered or invited or reported you. (Last interaction)
If you push insert, /w [insert name here] will appear. That's the last dude that invited/whispered/reported you. There's no way to know if it's invite, whisper or report, aside from your memory (if you're sure that he didn't invite/whisper, it's a report).
There's no clear way to get a list of who reported you and it's quite hard to remember if he/she has invited you before, if you were in Match for example.
@Riddick I request a close. The answer is above.