accident
alarm
alert
attention
background
beware
black
button
careful
caution
concept
construction
danger
dangerous
design
error
exclamation
failure
forbidden
graphic
hazard
icon
illustration
industry
information
internet
isolated
label
mark
message
notice
problem
protection
red
risk
road
safety
secure
security
sign
signal
stop
symbol
traffic
triangle
warning
web
white
yellow