标志牌，警告牌的英文

• warning board

• 标志:    sign; mark; symbol; hallmark ...
• 牌:    plate; tablet; board; placar ...
• 警告牌:    notice board; warning board
• 标志牌:    denoter; designation plate; index tag; sign board; tab
• 警告牌:    caution board; caution plate; notice board; walking flag; warning board