To execute every order and respect every prohibition without fail; describes a situation where discipline or laws are strictly and effectively enforced.

Smoking is forbidden or prohibited; no smoking.

Literally, prohibitions are observed and orders are carried out; used as an idiom to describe the strict enforcement of rules and commands.

used to indicate that parking is forbidden; no parking

to forbid someone to go out; to ground as a disciplinary measure; to impose a curfew

Do not enter; commonly seen on road signs and at building entrances.

Forbidden; prohibited; banned

total ban; complete prohibition

Comprehensive Nuclear-Test-Ban Treaty; an international agreement that bans all nuclear explosions for both civilian and military purposes