wp-includes/meta.php:1661Unregisters a meta key from the list of registered keys.
$object_typestring$meta_keystring$object_subtypestringoptional''boolfunction unregister_meta_key( $object_type, $meta_key, $object_subtype = '' ) { global $wp_meta_keys; if ( ! registered_meta_key_exists( $object_type, $meta_key, $object_subtype ) ) { return false; } $args = $wp_meta_keys[ $object_type ][ $object_subtype ][ $meta_key ]; if ( isset( $args['sanitize_callback'] ) && is_callable( $args['sanitize_callback'] ) ) { if ( ! empty( $object_subtype ) ) { remove_filter( "sanitize_{$object_type}_meta_{$meta_key}_for_{$object_subtype}", $args['sanitize_callback'] ); } else { remove_filter( "sanitize_{$object_type}_meta_{$meta_key}", $args['sanitize_callback'] ); } } if ( isset( $args['auth_callback'] ) && is_callable( $args['auth_callback'] ) ) { if ( ! empty( $object_subtype ) ) { remove_filter( "auth_{$object_type}_meta_{$meta_key}_for_{$object_subtype}", $args['auth_callback'] ); } else { remove_filter( "auth_{$object_type}_meta_{$meta_key}", $args['auth_callback'] ); } } unset( $wp_meta_keys[ $object_type ][ $object_subtype ][ $meta_key ] ); // Do some clean up. if ( empty( $wp_meta_keys[ $object_type ][ $object_subtype ] ) ) { unset( $wp_meta_keys[ $object_type ][ $object_subtype ] ); } if ( empty( $wp_meta_keys[ $object_type ] ) ) { unset( $wp_meta_keys[ $object_type ] ); } return true;}Introduced in 4.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/meta.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.