Siemens SINUMERIK 840C - Manual (Page 6)

Safety notes
DANGER
This warning notice means that loss of life, severe personal injury or
substantial material damage will result if the appropriate precautions
are not taken.
WARNING
This warning notice means that loss of life, severe personal injury or
substantial material damage can result if the appropriate precautions
are not taken.
CAUTION
This warning notice (with warning triangle) means that a minor
personal injury can result if the appropriate precautions are not taken.
CAUTION
This warning notice (without warning triangle) means that a material
damage can result if the appropriate precautions are not taken.
NOTICE
This warning notice means that an undesired event or an undesired
state can result if the appropriate notices are not observed.