wp-includes/block-supports/custom-css.php:278Adds the filters to strip custom CSS from block content on save.
function wp_custom_css_kses_init_filters() { add_filter( 'content_save_pre', 'wp_strip_custom_css_from_blocks', 8 ); add_filter( 'content_filtered_save_pre', 'wp_strip_custom_css_from_blocks', 8 );}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/custom-css.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.