‘Tis the season for muggy, oppressive weather, the kind that saps the energy and destroys the initiative . . . not the best kind of weather in which to be doing revisions, but still, revisions must be done.
A few of the things that get taken care of in revision, at least by me:
Turning a suitable number of semicolons into either periods or commas, as appropriate. I am, as I’ve admitted here before, one of those writers with a tendency to love semicolons not wisely, but too well, and getting rid of at least one in three isn’t going to hurt the story and will probably improve it.
Double-checking the continuity, in order to make sure that characters don’t refer to things other characters have told them before they’ve actually been told, and similar stuff. When you’re the bead-stringing, rather than the linear, sort of writer, this is a matter of particular concern.
Getting rid of any zero-draft filler material and placeholders that may have lingered in the text even through subsequent iterations. A tertiary character may have been referred to as [NameOfCharacter] while the plotline was still being spun out, for example, and now that he’s been promoted to Bob the Delivery Guy it’s a good idea to make certain that all the instances of square brackets have been cleaned up.
Generally smoothing out any sentences that are still too bumpy for my liking, and fixing up anything else that doesn’t feel quite right.
All I can say is, it’s a good thing that I like doing revisions. I’d hate to be doing something that I didn’t like, here in the hazy humid days of summer.
Dr. Doyle's Blog 
Filler labels occur in chrono-normative writing processes too: the last thing I want to do when I am really getting words down is stop to make up a name for a casual character/shop/street, so I stick in a label.
I always fix them when redrafting, and always run a search for ‘[‘ (and ‘{‘ just to make sure). Yet somehow every time a beta reader sends me an email making a joke about someone being called ‘Mr [NAME]’.