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filter is not described

delete_(meta_type)_metadata_by_mid filter-hook . WP 5.0.0

Filters whether to delete metadata of a specific type by meta ID.

The dynamic portion of the hook, $meta_type, refers to the meta object type (comment, post, term, or user). Returning a non-null value will effectively short-circuit the function.

Usage

add_filter( 'delete_(meta_type)_metadata_by_mid', 'filter_function_name_5115', 10, 2 );
function filter_function_name_5115( $delete, $meta_id ){
	// filter...

	return $delete;
}
$delete(null/true/false)
Whether to allow metadata deletion of the given type.
$meta_id(int)
Meta ID.

Where the hook is called

delete_metadata_by_mid()
wp-includes/meta.php 776
$check = apply_filters( "delete_{$meta_type}_metadata_by_mid", null, $meta_id );

Where the hook is used (in WP core)

wp-includes/default-filters.php 107
add_filter( 'delete_term_metadata_by_mid', 'wp_check_term_meta_support_prefilter' );