alert
attention
beware
black
blue
cable
careful
caution
danger
dangerous
electric
electrical
electricity
energy
exclamation
hazard
hazardous
high
industrial
industry
line
mark
metal
photo
point
power
precaution
pylon
red
risk
risky
safety
security
shock
sign
signage
signal
sky
steel
supply
symbol
technology
tower
transmission
triangle
triangular
voltage
warn
white