WordPress at a glance
filter is not described

disable_categories_dropdown filter-hook . WP 4.6.0

Filters whether to remove the 'Categories' drop-down from the post list table.

Usage

add_filter( 'disable_categories_dropdown', 'filter_function_name_2481', 10, 2 );
function filter_function_name_2481( $disable, $post_type ){
	// filter...

	return $disable;
}
$disable(true/false)
Whether to disable the categories drop-down.
Default: false
$post_type(string)
Post type slug.

Where the hook is called

WP_Posts_List_Table::categories_dropdown()
wp-admin/includes/class-wp-posts-list-table.php 431
if ( false !== apply_filters( 'disable_categories_dropdown', false, $post_type ) ) {

Where the hook is used (in WP core)

Does not used.