The Elwood City Public Library has a sign that says "NO TALKING" during the intro to "D.W.'s Library Card". However, when D.W. demands she wants Hopalong the Frog, she is heard being a nuisance and doing it in front of librarian Ms. Turner who's at her desk. So really, D.W. would be caught and ordered to be quiet or leave the library for causing a nuisance in places with these noise-ordinance rules.
During the sequence of D.W. demanding that she check out Hopalong the Frog, despite that it's checked out and still not back in, when Ms. Turner walks by D.W. house while the latter looks out the window, she says "Not yet, D.W." and then D.W. groans in return. D.W. would not have been able to hear the librarian tell her, unless the librarian were to have come to the window.