criminal trespass 2nd includes a fence or signs to announce posting. 3rd would be climbing a fence or walking under the posted signs

criminal trespass 3rd does not, just knowingly entering onto premises/property. If you unknowingly cross the property line from a place you have permission to one that you don't then no criminal act. 3rd would be driving across the city to some lake that you have no permission on any land adjoining it and going onto the property that you damn well know ain't yers....

purple paint law is posting the land against trespass....not hunting

all land in Al is posted by law, with or without signs, against hunting without landowner permission...no trespassing. You can get a ticket for trespass AND hunting w/o permission for the same offense.

you can be arrested for fishing on private property without permission if posted. You could be arrested for criminal trespass3rd without the signs or 2nd with the signs.