How to design placards?

However, some suggestions can be made.

Different placards are written in different ways.

But most of them have to

(1) is concise and easy to understand, easy to read and remember.

(2) targeted, can grasp the eyes and hearts of the audience, such as "a drop of wine from the driver, two tears from relatives"

(3) keep pace with the times. Use modern civilized sentences, such as "the grass is green, the first step is compassion" instead of "don't trample on the grass"

(4) Under normal circumstances, the slogan (signboard) should be signed, indicating the abbreviation of the production unit. Sometimes you don't write.