wp-includes/block-supports/anchor.php:17Registers the anchor block attribute for block types that support it.
$block_typeWP_Block_Typefunction wp_register_anchor_support( WP_Block_Type $block_type ) { if ( ! block_has_support( $block_type, array( 'anchor' ) ) ) { return; } if ( ! isset( $block_type->attributes ) ) { $block_type->attributes = array(); } if ( ! array_key_exists( 'anchor', $block_type->attributes ) ) { $block_type->attributes['anchor'] = array( 'type' => 'string', ); }}Introduced in 7.0.0. Unchanged from 7.0.4 through 7.1.0.
Signature, return type and hooks compared across 2 parsed releases.
src/wp-includes/block-supports/anchor.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.