accident
advice
alarm
alert
attention
background
beware
black
careful
caution
danger
dangerous
design
error
exclamation
failure
flat
graphic
hazard
help
icon
illustration
importance
important
information
interface
internet
isolated
mark
message
notice
point
precaution
problem
risk
road
safety
secure
security
sign
signal
stop
symbol
traffic
triangle
warn
warning
web
yellow