Está prohibido fumar.
(Write advertisements or signs for the situations described. Use impersonal constructions with se.)
If you post your sign or ad, someone may be able to check it.
Se prohíbe fumar - Smoking is prohibited.
Se ruega no fumar - Please do not smoke.
Se solicita no fumar - No smoking is requested.
Se advierte que está prohibido fumar - It is warned that smoking is prohibited.
Se recuerda que está prohibido fumar - It is reminded that smoking is prohibited.