Codes on Alerts and Indicators
| Alert code | Meaning |
|---|---|
| Alarm | A high priority alert requiring immediate attention and action |
| Alert | An announcement of abnormal situations and conditions requiring attentions |
| Caution | Lowest priority of an alert. Awareness of a condition which does not warrant an alarm or warning condition, but still requires attention out of the ordinary consideration of the situation or of given information |
| Warning | Condition requiring immediate attention, but not immediate action. |
Source: IMO Res. A1021(26)
(VTS40, IALA Guideline no. 1110 refers)