This is the 10091st most frequent Polish word.
biblioteczne
"Biblioteczne" means "library-related" or "pertaining to a library."
In this sentence, 'biblioteczny' is used as an adjective to describe the type of orderliness, specifically related to the context of a library.
Porządek biblioteczny jest wymagany.
Library orderliness is required.
Here, 'biblioteczne' functions as an adjective qualifying the noun 'książki' (books), indicating that the books belong or pertain to a library.
Znalazłem stare książki biblioteczne.
I found some old library books.
In the final example, 'biblioteczną' modifies 'kartę' (card), showing possession or association with a library.