accident
alarm
alert
attention
black
brake
button
collision
concept
connection
design
error
filled
flat
forced stop
glyph
graphic
hazard
icon
illustration
importance
important
indicator
information
internet
isolated
logo
message
network
no
notification
occasion
phone
pointer
priority
risk
safety
security
sign
silhouette
solid
stencil
symbol
telephone
threat
triangle
warning
web
zone