* Before HTML insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#the-before-html-insertion-mode

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_BEFORE_HTML = 'insertion-mode-before-html';

	/**

	 * Before head insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-beforehead

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_BEFORE_HEAD = 'insertion-mode-before-head';

	/**

	 * In head insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-inhead

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_HEAD = 'insertion-mode-in-head';

	/**

	 * In head noscript insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-inheadnoscript

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_HEAD_NOSCRIPT = 'insertion-mode-in-head-noscript';

	/**

	 * After head insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-afterhead

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_AFTER_HEAD = 'insertion-mode-after-head';

	/**

	 * In table insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-intable

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_TABLE = 'insertion-mode-in-table';

	/**

	 * In table text insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-intabletext

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_TABLE_TEXT = 'insertion-mode-in-table-text';

	/**

	 * In caption insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-incaption

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_CAPTION = 'insertion-mode-in-caption';

	/**

	 * In column group insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-incolumngroup

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_COLUMN_GROUP = 'insertion-mode-in-column-group';

	/**

	 * In table body insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-intablebody

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_TABLE_BODY = 'insertion-mode-in-table-body';

	/**

	 * In row insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-inrow

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_ROW = 'insertion-mode-in-row';

	/**

	 * In cell insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-incell

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_CELL = 'insertion-mode-in-cell';

	/**

	 * In select insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-inselect

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_SELECT = 'insertion-mode-in-select';

	/**

	 * In select in table insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-inselectintable

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_SELECT_IN_TABLE = 'insertion-mode-in-select-in-table';

	/**

	 * In template insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-intemplate

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_TEMPLATE = 'insertion-mode-in-template';

	/**

	 * After body insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-afterbody

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_AFTER_BODY = 'insertion-mode-after-body';

	/**

	 * In frameset insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-inframeset

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_IN_FRAMESET = 'insertion-mode-in-frameset';

	/**

	 * After frameset insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#parsing-main-afterframeset

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_AFTER_FRAMESET = 'insertion-mode-after-frameset';

	/**

	 * After after body insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#the-after-after-body-insertion-mode

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_AFTER_AFTER_BODY = 'insertion-mode-after-after-body';

	/**

	 * After after frameset insertion mode for full HTML parser.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#the-after-after-frameset-insertion-mode

	 * @see WP_HTML_Processor_State::$insertion_mode

	 *

	 * @var string

	 */

	const INSERTION_MODE_AFTER_AFTER_FRAMESET = 'insertion-mode-after-after-frameset';

	/**

	 * The stack of template insertion modes.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/#the-insertion-mode:stack-of-template-insertion-modes

	 *

	 * @var array<string>

	 */

	public $stack_of_template_insertion_modes = array();

	/**

	public $stack_of_open_elements;

	public $active_formatting_elements;

	 * @deprecated 6.8.0 WP_HTML_Processor tracks the context_node internally.

	 * @var null

	 * The recognized encoding of the input byte stream.

	 *

	 * > The stream of code points that comprises the input to the tokenization

	 * > stage will be initially seen by the user agent as a stream of bytes

	 * > (typically coming over the network or from the local file system).

	 * > The bytes encode the actual characters according to a particular character

	 * > encoding, which the user agent uses to decode the bytes into characters.

	 *

	 * @since 6.7.0

	 *

	 * @var string|null

	 */

	public $encoding = null;

	/**

	 * The parser's confidence in the input encoding.

	 *

	 * > When the HTML parser is decoding an input byte stream, it uses a character

	 * > encoding and a confidence. The confidence is either tentative, certain, or

	 * > irrelevant. The encoding used, and whether the confidence in that encoding

	 * > is tentative or certain, is used during the parsing to determine whether to

	 * > change the encoding. If no encoding is necessary, e.g. because the parser is

	 * > operating on a Unicode stream and doesn't have to use a character encoding

	 * > at all, then the confidence is irrelevant.

	 *

	 * @since 6.7.0

	 *

	 * @var string

	 */

	public $encoding_confidence = 'tentative';

	/**

	 * HEAD element pointer.

	 *

	 * @since 6.7.0

	 *

	 * @see https://html.spec.whatwg.org/multipage/parsing.html#head-element-pointer

	 *

	 * @var WP_HTML_Token|null

	 */

	public $head_element = null;

	/**

	 * FORM element pointer.

	 *

	 * > points to the last form element that was opened and whose end tag has

	 * > not yet been seen. It is used to make form controls associate with

	 * > forms in the face of dramatically bad markup, for historical reasons.

	 * > It is ignored inside template elements.

	 *

	 * @todo This may be invalidated by a seek operation.

	 *

	 * @see https://html.spec.whatwg.org/#form-element-pointer

	 *

	 * @since 6.7.0

	 *

	 * @var WP_HTML_Token|null

	 */

	public $form_element = null;

	/**