The Death Eaters have full members (those with the Dark Mark) and affiliates (Fenrir Greyback, Scabior, etc) -- is it the same for the Order?
I'm wondering if Mundungus "Dung" Fletcher was actually part of the Order of the Phoenix, or whether he was more of an affiliate. On one hand, in Deathly Hallows, we learn that Dumbledore instructed Snape to plant the idea of the Seven Potters with Mundungus using a Confundus Charm, and the Order subsequently used the idea. Furthermore, Dung is trusted to watch over Harry in Order of the Phoenix, a task which he fails at miserably, as the Dementor attacks on Harry and Dudley occur while Dung has absconded from his post at Privet Drive to go see about some stolen cauldrons. He is trusted enough for the Order to let him into No. 12 Grimmauld and to know that is the headquarters of the Order of the Phoenix.
On the other hand, Dung is a sneak thief who cleans out No. 12 Grimmauld and ends up being responsible for the the Slytherin locket Horcrux getting to Dolores Umbridge, and abandons Mad-Eye Moody in the Battle of the Seven Potters in Deathly Hallows, during which Moody is killed. We don't know what would've happened if Dung had not Disapparated from Moody's side, but if he had stuck around, it's possible he could have blocked a curse or stunned the Death Eater before the Death Eater could kill Moody.
Is there any canon, or a quote from J.K. Rowling, that verifies whether or not Mundungus Fletcher was a full member of the Order of the Phoenix?
Please, no HP Wikia or Wiki answers.