Specifies if a user's feedback score is or is not countable. This field is returned only when a user's feedback score is not countable (value is false).
Only feedback left by verified users can count toward the aggregate score of another user. If a user is not verified and leaves a feedback, then later becomes verified, that feedback will still not be counted. Or, if a user is verified and at some later date changes to unverified status, the feedback left while the user was verified remains countable. So you cannot determine a user's current verification status from whether or not feedback they've left is or was countable. Whether or not feedback is countable has nothing to do with the verification status of the one receiving the comment, only the one leaving the feedback.
See the
Field Index to learn which calls use Countable.