It is illegal for any person to enter upon the property of another or into an area or structure on such property (whether such property, area or structure is public or private), when such entrance is plainly forbidden by signs or otherwise or when the property, area or structure is enclosed, except when such entrance is in line of duty, or with the expressed, or tacit consent of the owner or person in charge, or otherwise by authority of law or ordinance. (Prior Code, Chapter 14, as amended)