THESE TWO NOTICES appear on adjacent walls in University College Hospital. Both say the same thing.
Note how the amateur version goes to great lengths to try to make the text stand out: it’s set in capitals plus bold plus underline, all in an attempt to create extra emphasis. But if it’s the only text on the notice, it will stand out anyway; it doesn’t need to compete with itself.
Devoid of capitals, underlines and bold text, the much more restrained professional version of the notice is much more effective.