WordPress at a glance
function is not described

unescape_invalid_shortcodes() WP 4.2.3

Remove placeholders added by do_shortcodes_in_html_tags().

No Hooks.

Return

String. Content with placeholders removed.

Usage

unescape_invalid_shortcodes( $content );
$content(string) (required)
Content to search for placeholders.

Code of unescape invalid shortcodes: wp-includes/shortcodes.php WP 5.2.2

<?php
function unescape_invalid_shortcodes( $content ) {
	// Clean up entire string, avoids re-parsing HTML.
	$trans = array(
		'&#91;' => '[',
		'&#93;' => ']',
	);

	$content = strtr( $content, $trans );

	return $content;
}