Choosing KDP categories

Everything below is quoted from Amazon's own help pages, with the page and the date it was read.

Source: "KDP Categories", https://kdp.amazon.com/en_US/help/topic/G200652170, read 2026-09-28.

"you can select 3 categories"
"We do not tolerate categorization that misleads readers"

A category unrelated to the book may be removed or changed by KDP, so a category is chosen because it truly describes the book, never because it looks easy to rank in.