This family of measures consists of installation of prohibition signs to address trespassing. Prohibitive signs tell to potential trespassers that their behaviour is illegal, forbidden and punishable.

It is considered a public awareness and educational family because it instructs people about what is allowed or forbidden, and occasionally informs them about the existing enforcement measures or surveillance measures (e.g. what is the fine for trespassing).

Measures in this family are often referred to as: signage, sign, posted information, interdiction, etc.