Over the years, there have been many posts seeking and recommending "age-appropriate" books for advanced readers.
(Crowd-sourced lists of recommended books, here: http://giftedissues.davidsongifted.org/BB/ubbthreads.php/forums/4/1/Recommended_Resources.html)

Parental requests for "age-appropriate" materials typically indicate a desire for some combination of:
- advanced vocabulary,
- varied sentence structure,
- material providing deeper knowledge, connections, and insight,
... while being free from:
- sexual content,
- violence and abuse,
- strong negative emotion,
- complex or conflicting emotional processing.

In recent years, there have been increasing accounts of parents becoming aware of materials in school libraries, which they deem age-inappropriate for the children for whom the materials have been curated and approved. Several states have separated/disassociated from the American Library Association (ALA).

This has given rise to the formation of the World Library Association, a new national alternative to the American Library Association.

Introducing World Library Association:
1. WLA website home - https://worldlibraryassociation.org/
2. WLA website, about - https://worldlibraryassociation.org/about/
3. WLA services - https://worldlibraryassociation.org/services/

The long-established American Library Association:
1. ALA website - https://www.ala.org/
2. ALA list of most challenged books of 2022 - https://www.ala.org/advocacy/bbooks/frequentlychallengedbooks/top10
3. ALA President for 2023-2024 - Emily Drabinski.