What's a placard?

A placard is a kind of sign. It can have a bunch of different information on it.

Most you’ll see are notices such as “Do Not Enter” “Hazardous” “Confined Space: No Entry Without Proper Authorization.” Such like that.

Hope that helped. 8D

Hell, it could be written on a piece of paper as long at it’s got the proper information required by law.

Most you see are the HazMat signs on the sides of trucks. A square angled at 45 degrees to mimic a diamond shape. There are then 3 different things you’d see on it: at the top you’d see a pictograph of the category under which the hazardous material falls, in the center a 4 digit number that corresponds with the hazardous material itself (the number describes the material in detail in the HazMat book) then on the bottom of the diamond is the category in number form to which the material falls under.

Another placard is the sticker you see above a door at any business “This door to remain unlocked during normal business hours.”

Then you’ve also got the handicap placard that just hangs on the rear view mirror.

So you’ve got 3 different types of materials right there, HazMat placard: plastic with an adhesive backing; door sign: sticker; handicap placard: plastic.

Take your pick. Look it up on Wikipedia, there’s not much there, but it’ll help a little.