User written checking callback return codes.

Values:

IG_REC_CW_IMPOSSIBLE	The application finds that the recognized string passed to the checking function is not possible for the given zone.
IG_REC_CW_UNLIKELY	The application finds that the recognized string passed to the checking function is unlikely to be acceptable for the given zone.
IG_REC_CW_UNRESOLVED	The application's checking function cannot make a decision on the acceptability of the string for the zone.
IG_REC_CW_POSSIBLE	The application finds that the recognized string passed to the checking function is possible to be acceptable for the given zone.
IG_REC_CW_SURE	The application finds that the recognized string passed to the checking function is certainly acceptable for the given zone.

Remarks:

This enum defines the possible values that a user-written checking callback function should return. This type of function should be written for zones where recognition accuracy can be improved by providing the recognition module with application-derived, additional checking information.