# state:

Is used in conjunction with version: to mark the maturity or activation of a plugin.

 # state: stable

Other typicaly values are beta, alpha, testing, obsolete etc.
Or if used for activation states: off, disabled, hidden etc.

(This field was originally called status. And that's the more common designation. This is kind of a post-rationalization, but for the context of plugin management it makes sense to double as indicator for the effective state as well.)