advice
alarm
allowed
attention
background
block
caution
danger
deny
direction
entry
forbid
forbidden
gesture
graphic
halt
hand
hazard
highway
human
icon
illustration
information
isolated
law
message
no
not
octagon
palm
pictogram
prohibiting
protest
red
restrict
restriction
restrictive
road
safety
sign
signal
stop
symbol
traffic
transportation
warn
warning
white