As a companion to my other feature request regarding flag statuses, and a previous feature request for the same thing, I would like to request the ability to get a flag's status via the API.
There are applications that allow you to flag questions, answers and comments without being on a Stack Exchange site. Occasionally, these flags are declined and it'd be useful to show these statuses on the 3rd party applications.
Additionally, the 3rd party developer could utilize this information to prevent an influx of invalid flags by a single user (ie. a user flags multiple things that are declined in a very short period of time).