YASKAWA SGMJV User Manual page 6

Indicates precautions that, if not heeded, could result in relatively serious
CAUTION
or minor injury, damage to the product, or faulty operation.
In some situations, the precautions indicated could have serious
consequences if not heeded.
Indicates prohibited actions that must not be performed. For example,
PROHIBITED
this symbol would be used to indicate that fire is prohibited as follows:
Indicates compulsory actions that must be performed. For example, this
MANDATORY
symbol would be used to indicate that grounding is compulsory as
follows:
vi