(a) A person “enters or remains unlawfully” in or upon premises when he or she is not then licensed, invited, or otherwise privileged to so enter or remain.

(b) A license or privilege to enter or remain in a building which is only partly open to the public is not a license or privilege to enter or remain in that part of a building which is not open to the public. A person who enters or remains upon unimproved and apparently unused land which is neither fenced nor otherwise enclosed in a manner designed to exclude intruders, does so with license and privilege unless notice against trespass is personally communicated to him or her by the owner of the land or some over authorized person, or unless notice is given by posting in a conspicuous manner. Land that is used for growing an agricultural crop or crops, other than timber, is not unimproved and apparently unused land if a crop or any other sign of cultivation is clearly visible or if notice is given by posting in a conspicuous manner. Similarly, a field fenced in any manner is not unimproved and apparently unused land.