pre_get_posts (tag)
Changing the Number of Posts Displayed on a Page
Learn how to change WordPress post listings per page using the pre_get_posts hook.
Enabling a Custom Post Type in Search Results
Add a custom post type to WordPress search results by setting post_type during search queries.
Excluding pages from search results
Exclude pages from WordPress search results using the pre_get_posts hook.
Excluding Categories on the Front Page
How to exclude specific categories from appearing on the blog front page using WordPress query hooks.