Warnings and cautions protect people and equipment. A warning tells the reader about a risk of injury or death. A caution tells the reader about a risk of damage to equipment or material. In STE, a warning or caution starts with a clear command and then explains the risk.
Warning or caution?
- Warning: a risk to people (injury or death).
- Caution: a risk to equipment or material (damage).
- Note: extra information, no risk. A note is not a warning or a caution.
- Use the correct type. Too many warnings make readers ignore them.
Start with a clear command
- Start with what the reader must do or must not do: "Disconnect the power supply before you…", "Do not…".
- Do not start with "Be careful" or "It is important to be aware". These do not tell the reader what to do.
Then give the risk
- After the command, give a short explanation: what can happen if the reader does not obey.
- Be specific: "High voltage can cause death or injury", not "This can be dangerous".
Put it before the step
- Put the warning or caution before the step where the risk occurs. The reader must read it before doing the step.
Keep it short
- Use the same sentence rules as in procedures.
- One warning or caution is about one risk. If there are two risks, write two.