issing-quote-before-doctype-system-identifier parse error. Set the * > current DOCTYPE token's force-quirks flag to on. Reconsume in the bogus DOCTYPE state. */ if ( '"' !== $closer_quote && "'" !== $closer_quote ) { return new self( $doctype_name, $doctype_public_id, $doctype_system_id, true ); } ++$at; $identifier_length = strcspn( $doctype_html, $closer_quote, $at, $end - $at ); $doctype_system_id = str_replace( "\0", "\u{FFFD}", substr( $doctype_html, $at, $identifier_length ) ); $at += $identifier_length; if ( $at >= $end || $closer_quote !== $doctype_html[ $at ] ) { return new self( $doctype_name, $doctype_public_id, $doctype_system_id, true ); } return new self( $doctype_name, $doctype_public_id, $doctype_system_id, false ); } } Explore – Nos Dushi Bida