wp-includes/class-wp-icons-registry.php:210Unregisters an icon.
$icon_namestringbool public function unregister( $icon_name ) { if ( ! $this->is_registered( $icon_name ) ) { _doing_it_wrong( __METHOD__, sprintf( /* translators: %s: Icon name. */ __( 'Icon "%s" is not registered.' ), $icon_name ), '7.1.0' ); return false; } unset( $this->registered_icons[ $icon_name ] ); return true; }Introduced in 7.1.0.
Signature, return type and hooks compared across 1 parsed release.
src/wp-includes/class-wp-icons-registry.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.