This enumeration represents capability control messages.

Values:

IG_TW_MSG_GET	Get one or more values.
IG_TW_MSG_GETCURRENT	Get current value.
IG_TW_MSG_GETDEFAULT	Get default (e.g., power up) value.
IG_TW_MSG_GETFIRST	Get first value.
IG_TW_MSG_GETNEXT	Get next value.
IG_TW_MSG_QUERYSUPPORT	Query capability support.
IG_TW_MSG_RESET	Set current value to default value.
IG_TW_MSG_SET	Set one or more values.