Ключевые слова: accident, alert, alphabet, attention, background, banner, barrier, board, building, business, care, caution, concept, construction, crime, danger, dangerous, design, fire, header, information, isolated, letter, message, note, object, police, protect, protection, quote, restricted, risk, safe, safety, security, sign, stop, symbol, tape, text, traffic, typo, typography, warning, white, wood, wooden, word, work, zone,