Warning sign

See also: Warning road sign.

Warning signs can indicate any potential hazard, obstacle or condition requiring special attention.

• 
  Sign in Niagara Falls, Ontario, warning people not to climb over guard rail overlooking the Niagara River.
• 
  Warning entrance sign to an exhibitions at Palazzo Pitti museum compound, Florence, Italy.
• 
  "Beware of Dog" sign at the Glasgow Necropolis
• 
  Wet floor sign with warnings in both English and Spanish
• 
  Caution wet floor sign
• 
  A sign indicating that no parking is allowed on a lane
• bio hazard
  bio hazard
• 
  laser
• 
• 
  Dog-related signs