WEST DES MOINES, Iowa (AP) — State restrictions on books that can be made available to Iowa students have prompted some Des Moines-area school districts to post disclaimers on Little Free Libraries.

Earlier this year the Iowa Legislature approved a law that bans books that describe sex acts from libraries and classrooms, forcing school districts to examine their books and remove any in violation of the new rules. The bill also requires school districts to maintain online lists of books that are available to students.

That law has led at least two suburban school districts to place disclaimers on Little Free Libraries, free-standing outdoor displays where people are encouraged to share books.

At Webster Elementary in the Urbandale school district, the Des Moines Register reports that a sign has been posted stating, “This ‘little library’ is not funded, sponsored, endorsed or maintained by the Urbandale Community School District and is not in any way part of the Urbandale Schools library program.”

A school district spokesperson didn’t respond to an email and phone message from The Associated Press seeking a comment about the disclaimer.

In the West Des Moines school district, spokesperson Laine Buck said the district planned to add signs on any little libraries on school grounds but wouldn’t remove the exchanges.

“They are intended for free book sharing, and because it is a community resource that we believe the broader community appreciates, we currently do not have plans to remove any from district property,” Buck said.

The Des Moines school district has a Little Free Library outside at least one school but doesn’t plan to post a disclaimer, a spokesperson said.

Margret Aldrich, a spokesperson for Little Free Library, a nonprofit based in St. Paul, Minnesota, said it was disappointing that school districts felt a need to post disclaimers but that it was good they had found a solution that enabled the book-sharing program to continue. Aldrich said she wasn’t aware of anything similar in other states.