>current_node_is( $token_name ) ) {
					// This is a parse error.
				}

				$this->state->stack_of_open_elements->pop_until( $token_name );
				$this->state->active_formatting_elements->clear_up_to_last_marker();
				return true;

			/*
			 * > A start tag whose tag name is "table"
			 */
			case '+TABLE':
				/*
				 * > If the Document is not set to quirks mode, and the stack of open elements
				 * > has a p element in button scope, then close a p element.
				 */
				if (
					WP_HTML_Tag_Processor::QUIRKS_MODE !== $this->compat_mode &&
					$this->state->stack_of_open_elements->has_p_in_button_scope()
				) {
					$this->close_a_p_element();
				}

				$this->insert_html_element( $this->state->current_token );
				$this->state->frameset_ok    = false;
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
				return true;

			/*
			 * > An end tag whose tag name is "br"
			 *
			 * This is prevented from happening because the Tag Processor
			 * reports all closing BR tags as if they were opening tags.
			 */

			/*
			 * > A start tag whose tag name is one of: "area", "br", "embed", "img", "keygen", "wbr"
			 */
			case '+AREA':
			case '+BR':
			case '+EMBED':
			case '+IMG':
			case '+KEYGEN':
			case '+WBR':
				$this->reconstruct_active_formatting_elements();
				$this->insert_html_element( $this->state->current_token );
				$this->state->frameset_ok = false;
				return true;

			/*
			 * > A start tag whose tag name is "input"
			 */
			case '+INPUT':
				$this->reconstruct_active_formatting_elements();
				$this->insert_html_element( $this->state->current_token );

				/*
				 * > If the token does not have an attribute with the name "type", or if it does,
				 * > but that attribute's value is not an ASCII case-insensitive match for the
				 * > string "hidden", then: set the frameset-ok flag to "not ok".
				 */
				$type_attribute = $this->get_attribute( 'type' );
				if ( ! is_string( $type_attribute ) || 'hidden' !== strtolower( $type_attribute ) ) {
					$this->state->frameset_ok = false;
				}

				return true;

			/*
			 * > A start tag whose tag name is one of: "param", "source", "track"
			 */
			case '+PARAM':
			case '+SOURCE':
			case '+TRACK':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is "hr"
			 */
			case '+HR':
				if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
					$this->close_a_p_element();
				}
				$this->insert_html_element( $this->state->current_token );
				$this->state->frameset_ok = false;
				return true;

			/*
			 * > A start tag whose tag name is "image"
			 */
			case '+IMAGE':
				/*
				 * > Parse error. Change the token's tag name to "img" and reprocess it. (Don't ask.)
				 *
				 * Note that this is handled elsewhere, so it should not be possible to reach this code.
				 */
				$this->bail( "Cannot process an IMAGE tag. (Don't ask.)" );
				break;

			/*
			 * > A start tag whose tag name is "textarea"
			 */
			case '+TEXTAREA':
				$this->insert_html_element( $this->state->current_token );

				/*
				 * > If the next token is a U+000A LINE FEED (LF) character token, then ignore
				 * > that token and move on to the next one. (Newlines at the start of
				 * > textarea elements are ignored as an authoring convenience.)
				 *
				 * This is handled in `get_modifiable_text()`.
				 */

				$this->state->frameset_ok = false;

				/*
				 * > Switch the insertion mode to "text".
				 *
				 * As a self-contained node, this behavior is handled in the Tag Processor.
				 */
				return true;

			/*
			 * > A start tag whose tag name is "xmp"
			 */
			case '+XMP':
				if ( $this->state->stack_of_open_elements->has_p_in_button_scope() ) {
					$this->close_a_p_element();
				}

				$this->reconstruct_active_formatting_elements();
				$this->state->frameset_ok = false;

				/*
				 * > Follow the generic raw text element parsing algorithm.
				 *
				 * As a self-contained node, this behavior is handled in the Tag Processor.
				 */
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * A start tag whose tag name is "iframe"
			 */
			case '+IFRAME':
				$this->state->frameset_ok = false;

				/*
				 * > Follow the generic raw text element parsing algorithm.
				 *
				 * As a self-contained node, this behavior is handled in the Tag Processor.
				 */
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is "noembed"
			 * > A start tag whose tag name is "noscript", if the scripting flag is enabled
			 *
			 * The scripting flag is never enabled in this parser.
			 */
			case '+NOEMBED':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is "select"
			 */
			case '+SELECT':
				$this->reconstruct_active_formatting_elements();
				$this->insert_html_element( $this->state->current_token );
				$this->state->frameset_ok = false;

				switch ( $this->state->insertion_mode ) {
					/*
					 * > If the insertion mode is one of "in table", "in caption", "in table body", "in row",
					 * > or "in cell", then switch the insertion mode to "in select in table".
					 */
					case WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE:
					case WP_HTML_Processor_State::INSERTION_MODE_IN_CAPTION:
					case WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY:
					case WP_HTML_Processor_State::INSERTION_MODE_IN_ROW:
					case WP_HTML_Processor_State::INSERTION_MODE_IN_CELL:
						$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_SELECT_IN_TABLE;
						break;

					/*
					 * > Otherwise, switch the insertion mode to "in select".
					 */
					default:
						$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_SELECT;
						break;
				}
				return true;

			/*
			 * > A start tag whose tag name is one of: "optgroup", "option"
			 */
			case '+OPTGROUP':
			case '+OPTION':
				if ( $this->state->stack_of_open_elements->current_node_is( 'OPTION' ) ) {
					$this->state->stack_of_open_elements->pop();
				}
				$this->reconstruct_active_formatting_elements();
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is one of: "rb", "rtc"
			 */
			case '+RB':
			case '+RTC':
				if ( $this->state->stack_of_open_elements->has_element_in_scope( 'RUBY' ) ) {
					$this->generate_implied_end_tags();

					if ( $this->state->stack_of_open_elements->current_node_is( 'RUBY' ) ) {
						// @todo Indicate a parse error once it's possible.
					}
				}

				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is one of: "rp", "rt"
			 */
			case '+RP':
			case '+RT':
				if ( $this->state->stack_of_open_elements->has_element_in_scope( 'RUBY' ) ) {
					$this->generate_implied_end_tags( 'RTC' );

					$current_node_name = $this->state->stack_of_open_elements->current_node()->node_name;
					if ( 'RTC' === $current_node_name || 'RUBY' === $current_node_name ) {
						// @todo Indicate a parse error once it's possible.
					}
				}

				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is "math"
			 */
			case '+MATH':
				$this->reconstruct_active_formatting_elements();

				/*
				 * @todo Adjust MathML attributes for the token. (This fixes the case of MathML attributes that are not all lowercase.)
				 * @todo Adjust foreign attributes for the token. (This fixes the use of namespaced attributes, in particular XLink.)
				 *
				 * These ought to be handled in the attribute methods.
				 */
				$this->state->current_token->namespace = 'math';
				$this->insert_html_element( $this->state->current_token );
				if ( $this->state->current_token->has_self_closing_flag ) {
					$this->state->stack_of_open_elements->pop();
				}
				return true;

			/*
			 * > A start tag whose tag name is "svg"
			 */
			case '+SVG':
				$this->reconstruct_active_formatting_elements();

				/*
				 * @todo Adjust SVG attributes for the token. (This fixes the case of SVG attributes that are not all lowercase.)
				 * @todo Adjust foreign attributes for the token. (This fixes the use of namespaced attributes, in particular XLink in SVG.)
				 *
				 * These ought to be handled in the attribute methods.
				 */
				$this->state->current_token->namespace = 'svg';
				$this->insert_html_element( $this->state->current_token );
				if ( $this->state->current_token->has_self_closing_flag ) {
					$this->state->stack_of_open_elements->pop();
				}
				return true;

			/*
			 * > A start tag whose tag name is one of: "caption", "col", "colgroup",
			 * > "frame", "head", "tbody", "td", "tfoot", "th", "thead", "tr"
			 */
			case '+CAPTION':
			case '+COL':
			case '+COLGROUP':
			case '+FRAME':
			case '+HEAD':
			case '+TBODY':
			case '+TD':
			case '+TFOOT':
			case '+TH':
			case '+THEAD':
			case '+TR':
				// Parse error. Ignore the token.
				return $this->step();
		}

		if ( ! parent::is_tag_closer() ) {
			/*
			 * > Any other start tag
			 */
			$this->reconstruct_active_formatting_elements();
			$this->insert_html_element( $this->state->current_token );
			return true;
		} else {
			/*
			 * > Any other end tag
			 */

			/*
			 * Find the corresponding tag opener in the stack of open elements, if
			 * it exists before reaching a special element, which provides a kind
			 * of boundary in the stack. For example, a `</custom-tag>` should not
			 * close anything beyond its containing `P` or `DIV` element.
			 */
			foreach ( $this->state->stack_of_open_elements->walk_up() as $node ) {
				if ( 'html' === $node->namespace && $token_name === $node->node_name ) {
					break;
				}

				if ( self::is_special( $node ) ) {
					// This is a parse error, ignore the token.
					return $this->step();
				}
			}

			$this->generate_implied_end_tags( $token_name );
			if ( $node !== $this->state->stack_of_open_elements->current_node() ) {
				// @todo Record parse error: this error doesn't impact parsing.
			}

			foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
				$this->state->stack_of_open_elements->pop();
				if ( $node === $item ) {
					return true;
				}
			}
		}

		$this->bail( 'Should not have been able to reach end of IN BODY processing. Check HTML API code.' );
		// This unnecessary return prevents tools from inaccurately reporting type errors.
		return false;
	}

	/**
	 * Parses next element in the 'in table' insertion mode.
	 *
	 * This internal function performs the 'in table' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-intable
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_table(): bool {
		$token_name = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( parent::is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$token_name}";

		switch ( $op ) {
			/*
			 * > A character token, if the current node is table,
			 * > tbody, template, tfoot, thead, or tr element
			 */
			case '#text':
				$current_node      = $this->state->stack_of_open_elements->current_node();
				$current_node_name = $current_node ? $current_node->node_name : null;
				if (
					$current_node_name && (
						'TABLE' === $current_node_name ||
						'TBODY' === $current_node_name ||
						'TEMPLATE' === $current_node_name ||
						'TFOOT' === $current_node_name ||
						'THEAD' === $current_node_name ||
						'TR' === $current_node_name
					)
				) {
					/*
					 * If the text is empty after processing HTML entities and stripping
					 * U+0000 NULL bytes then ignore the token.
					 */
					if ( parent::TEXT_IS_NULL_SEQUENCE === $this->text_node_classification ) {
						return $this->step();
					}

					/*
					 * This follows the rules for "in table text" insertion mode.
					 *
					 * Whitespace-only text nodes are inserted in-place. Otherwise
					 * foster parenting is enabled and the nodes would be
					 * inserted out-of-place.
					 *
					 * > If any of the tokens in the pending table character tokens
					 * > list are character tokens that are not ASCII whitespace,
					 * > then this is a parse error: reprocess the character tokens
					 * > in the pending table character tokens list using the rules
					 * > given in the "anything else" entry in the "in table"
					 * > insertion mode.
					 * >
					 * > Otherwise, insert the characters given by the pending table
					 * > character tokens list.
					 *
					 * @see https://html.spec.whatwg.org/#parsing-main-intabletext
					 */
					if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
						$this->insert_html_element( $this->state->current_token );
						return true;
					}

					// Non-whitespace would trigger fostering, unsupported at this time.
					$this->bail( 'Foster parenting is not supported.' );
					break;
				}
				break;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "caption"
			 */
			case '+CAPTION':
				$this->state->stack_of_open_elements->clear_to_table_context();
				$this->state->active_formatting_elements->insert_marker();
				$this->insert_html_element( $this->state->current_token );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_CAPTION;
				return true;

			/*
			 * > A start tag whose tag name is "colgroup"
			 */
			case '+COLGROUP':
				$this->state->stack_of_open_elements->clear_to_table_context();
				$this->insert_html_element( $this->state->current_token );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_COLUMN_GROUP;
				return true;

			/*
			 * > A start tag whose tag name is "col"
			 */
			case '+COL':
				$this->state->stack_of_open_elements->clear_to_table_context();

				/*
				 * > Insert an HTML element for a "colgroup" start tag token with no attributes,
				 * > then switch the insertion mode to "in column group".
				 */
				$this->insert_virtual_node( 'COLGROUP' );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_COLUMN_GROUP;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > A start tag whose tag name is one of: "tbody", "tfoot", "thead"
			 */
			case '+TBODY':
			case '+TFOOT':
			case '+THEAD':
				$this->state->stack_of_open_elements->clear_to_table_context();
				$this->insert_html_element( $this->state->current_token );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				return true;

			/*
			 * > A start tag whose tag name is one of: "td", "th", "tr"
			 */
			case '+TD':
			case '+TH':
			case '+TR':
				$this->state->stack_of_open_elements->clear_to_table_context();
				/*
				 * > Insert an HTML element for a "tbody" start tag token with no attributes,
				 * > then switch the insertion mode to "in table body".
				 */
				$this->insert_virtual_node( 'TBODY' );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > A start tag whose tag name is "table"
			 *
			 * This tag in the IN TABLE insertion mode is a parse error.
			 */
			case '+TABLE':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TABLE' ) ) {
					return $this->step();
				}

				$this->state->stack_of_open_elements->pop_until( 'TABLE' );
				$this->reset_insertion_mode_appropriately();
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is "table"
			 */
			case '-TABLE':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TABLE' ) ) {
					// @todo Indicate a parse error once it's possible.
					return $this->step();
				}

				$this->state->stack_of_open_elements->pop_until( 'TABLE' );
				$this->reset_insertion_mode_appropriately();
				return true;

			/*
			 * > An end tag whose tag name is one of: "body", "caption", "col", "colgroup", "html", "tbody", "td", "tfoot", "th", "thead", "tr"
			 */
			case '-BODY':
			case '-CAPTION':
			case '-COL':
			case '-COLGROUP':
			case '-HTML':
			case '-TBODY':
			case '-TD':
			case '-TFOOT':
			case '-TH':
			case '-THEAD':
			case '-TR':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is one of: "style", "script", "template"
			 * > An end tag whose tag name is "template"
			 */
			case '+STYLE':
			case '+SCRIPT':
			case '+TEMPLATE':
			case '-TEMPLATE':
				/*
				 * > Process the token using the rules for the "in head" insertion mode.
				 */
				return $this->step_in_head();

			/*
			 * > A start tag whose tag name is "input"
			 *
			 * > If the token does not have an attribute with the name "type", or if it does, but
			 * > that attribute's value is not an ASCII case-insensitive match for the string
			 * > "hidden", then: act as described in the "anything else" entry below.
			 */
			case '+INPUT':
				$type_attribute = $this->get_attribute( 'type' );
				if ( ! is_string( $type_attribute ) || 'hidden' !== strtolower( $type_attribute ) ) {
					goto anything_else;
				}
				// @todo Indicate a parse error once it's possible.
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is "form"
			 *
			 * This tag in the IN TABLE insertion mode is a parse error.
			 */
			case '+FORM':
				if (
					$this->state->stack_of_open_elements->has_element_in_scope( 'TEMPLATE' ) ||
					isset( $this->state->form_element )
				) {
					return $this->step();
				}

				// This FORM is special because it immediately closes and cannot have other children.
				$this->insert_html_element( $this->state->current_token );
				$this->state->form_element = $this->state->current_token;
				$this->state->stack_of_open_elements->pop();
				return true;
		}

		/*
		 * > Anything else
		 * > Parse error. Enable foster parenting, process the token using the rules for the
		 * > "in body" insertion mode, and then disable foster parenting.
		 *
		 * @todo Indicate a parse error once it's possible.
		 */
		anything_else:
		$this->bail( 'Foster parenting is not supported.' );
	}

	/**
	 * Parses next element in the 'in table text' insertion mode.
	 *
	 * This internal function performs the 'in table text' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-intabletext
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_table_text(): bool {
		$this->bail( 'No support for parsing in the ' . WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_TEXT . ' state.' );
	}

	/**
	 * Parses next element in the 'in caption' insertion mode.
	 *
	 * This internal function performs the 'in caption' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-incaption
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_caption(): bool {
		$tag_name = $this->get_tag();
		$op_sigil = $this->is_tag_closer() ? '-' : '+';
		$op       = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > An end tag whose tag name is "caption"
			 * > A start tag whose tag name is one of: "caption", "col", "colgroup", "tbody", "td", "tfoot", "th", "thead", "tr"
			 * > An end tag whose tag name is "table"
			 *
			 * These tag handling rules are identical except for the final instruction.
			 * Handle them in a single block.
			 */
			case '-CAPTION':
			case '+CAPTION':
			case '+COL':
			case '+COLGROUP':
			case '+TBODY':
			case '+TD':
			case '+TFOOT':
			case '+TH':
			case '+THEAD':
			case '+TR':
			case '-TABLE':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( 'CAPTION' ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				$this->generate_implied_end_tags();
				if ( ! $this->state->stack_of_open_elements->current_node_is( 'CAPTION' ) ) {
					// @todo Indicate a parse error once it's possible.
				}

				$this->state->stack_of_open_elements->pop_until( 'CAPTION' );
				$this->state->active_formatting_elements->clear_up_to_last_marker();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;

				// If this is not a CAPTION end tag, the token should be reprocessed.
				if ( '-CAPTION' === $op ) {
					return true;
				}
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/**
			 * > An end tag whose tag name is one of: "body", "col", "colgroup", "html", "tbody", "td", "tfoot", "th", "thead", "tr"
			 */
			case '-BODY':
			case '-COL':
			case '-COLGROUP':
			case '-HTML':
			case '-TBODY':
			case '-TD':
			case '-TFOOT':
			case '-TH':
			case '-THEAD':
			case '-TR':
				// Parse error: ignore the token.
				return $this->step();
		}

		/**
		 * > Anything else
		 * >   Process the token using the rules for the "in body" insertion mode.
		 */
		return $this->step_in_body();
	}

	/**
	 * Parses next element in the 'in column group' insertion mode.
	 *
	 * This internal function performs the 'in column group' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-incolgroup
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_column_group(): bool {
		$token_name = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( parent::is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$token_name}";

		switch ( $op ) {
			/*
			 * > A character token that is one of U+0009 CHARACTER TABULATION, U+000A LINE FEED (LF),
			 * > U+000C FORM FEED (FF), U+000D CARRIAGE RETURN (CR), or U+0020 SPACE
			 */
			case '#text':
				if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
					// Insert the character.
					$this->insert_html_element( $this->state->current_token );
					return true;
				}

				goto in_column_group_anything_else;
				break;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// @todo Indicate a parse error once it's possible.
				return $this->step();

			/*
			 * > A start tag whose tag name is "html"
			 */
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > A start tag whose tag name is "col"
			 */
			case '+COL':
				$this->insert_html_element( $this->state->current_token );
				$this->state->stack_of_open_elements->pop();
				return true;

			/*
			 * > An end tag whose tag name is "colgroup"
			 */
			case '-COLGROUP':
				if ( ! $this->state->stack_of_open_elements->current_node_is( 'COLGROUP' ) ) {
					// @todo Indicate a parse error once it's possible.
					return $this->step();
				}
				$this->state->stack_of_open_elements->pop();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
				return true;

			/*
			 * > An end tag whose tag name is "col"
			 */
			case '-COL':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "template"
			 * > An end tag whose tag name is "template"
			 */
			case '+TEMPLATE':
			case '-TEMPLATE':
				return $this->step_in_head();
		}

		in_column_group_anything_else:
		/*
		 * > Anything else
		 */
		if ( ! $this->state->stack_of_open_elements->current_node_is( 'COLGROUP' ) ) {
			// @todo Indicate a parse error once it's possible.
			return $this->step();
		}
		$this->state->stack_of_open_elements->pop();
		$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
		return $this->step( self::REPROCESS_CURRENT_NODE );
	}

	/**
	 * Parses next element in the 'in table body' insertion mode.
	 *
	 * This internal function performs the 'in table body' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-intbody
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_table_body(): bool {
		$tag_name = $this->get_tag();
		$op_sigil = $this->is_tag_closer() ? '-' : '+';
		$op       = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A start tag whose tag name is "tr"
			 */
			case '+TR':
				$this->state->stack_of_open_elements->clear_to_table_body_context();
				$this->insert_html_element( $this->state->current_token );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_ROW;
				return true;

			/*
			 * > A start tag whose tag name is one of: "th", "td"
			 */
			case '+TH':
			case '+TD':
				// @todo Indicate a parse error once it's possible.
				$this->state->stack_of_open_elements->clear_to_table_body_context();
				$this->insert_virtual_node( 'TR' );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_ROW;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is one of: "tbody", "tfoot", "thead"
			 */
			case '-TBODY':
			case '-TFOOT':
			case '-THEAD':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( $tag_name ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				$this->state->stack_of_open_elements->clear_to_table_body_context();
				$this->state->stack_of_open_elements->pop();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
				return true;

			/*
			 * > A start tag whose tag name is one of: "caption", "col", "colgroup", "tbody", "tfoot", "thead"
			 * > An end tag whose tag name is "table"
			 */
			case '+CAPTION':
			case '+COL':
			case '+COLGROUP':
			case '+TBODY':
			case '+TFOOT':
			case '+THEAD':
			case '-TABLE':
				if (
					! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TBODY' ) &&
					! $this->state->stack_of_open_elements->has_element_in_table_scope( 'THEAD' ) &&
					! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TFOOT' )
				) {
					// Parse error: ignore the token.
					return $this->step();
				}
				$this->state->stack_of_open_elements->clear_to_table_body_context();
				$this->state->stack_of_open_elements->pop();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is one of: "body", "caption", "col", "colgroup", "html", "td", "th", "tr"
			 */
			case '-BODY':
			case '-CAPTION':
			case '-COL':
			case '-COLGROUP':
			case '-HTML':
			case '-TD':
			case '-TH':
			case '-TR':
				// Parse error: ignore the token.
				return $this->step();
		}

		/*
		 * > Anything else
		 * > Process the token using the rules for the "in table" insertion mode.
		 */
		return $this->step_in_table();
	}

	/**
	 * Parses next element in the 'in row' insertion mode.
	 *
	 * This internal function performs the 'in row' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-intr
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_row(): bool {
		$tag_name = $this->get_tag();
		$op_sigil = $this->is_tag_closer() ? '-' : '+';
		$op       = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A start tag whose tag name is one of: "th", "td"
			 */
			case '+TH':
			case '+TD':
				$this->state->stack_of_open_elements->clear_to_table_row_context();
				$this->insert_html_element( $this->state->current_token );
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_CELL;
				$this->state->active_formatting_elements->insert_marker();
				return true;

			/*
			 * > An end tag whose tag name is "tr"
			 */
			case '-TR':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TR' ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				$this->state->stack_of_open_elements->clear_to_table_row_context();
				$this->state->stack_of_open_elements->pop();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				return true;

			/*
			 * > A start tag whose tag name is one of: "caption", "col", "colgroup", "tbody", "tfoot", "thead", "tr"
			 * > An end tag whose tag name is "table"
			 */
			case '+CAPTION':
			case '+COL':
			case '+COLGROUP':
			case '+TBODY':
			case '+TFOOT':
			case '+THEAD':
			case '+TR':
			case '-TABLE':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TR' ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				$this->state->stack_of_open_elements->clear_to_table_row_context();
				$this->state->stack_of_open_elements->pop();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is one of: "tbody", "tfoot", "thead"
			 */
			case '-TBODY':
			case '-TFOOT':
			case '-THEAD':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( $tag_name ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( 'TR' ) ) {
					// Ignore the token.
					return $this->step();
				}

				$this->state->stack_of_open_elements->clear_to_table_row_context();
				$this->state->stack_of_open_elements->pop();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is one of: "body", "caption", "col", "colgroup", "html", "td", "th"
			 */
			case '-BODY':
			case '-CAPTION':
			case '-COL':
			case '-COLGROUP':
			case '-HTML':
			case '-TD':
			case '-TH':
				// Parse error: ignore the token.
				return $this->step();
		}

		/*
		 * > Anything else
		 * >   Process the token using the rules for the "in table" insertion mode.
		 */
		return $this->step_in_table();
	}

	/**
	 * Parses next element in the 'in cell' insertion mode.
	 *
	 * This internal function performs the 'in cell' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-intd
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_cell(): bool {
		$tag_name = $this->get_tag();
		$op_sigil = $this->is_tag_closer() ? '-' : '+';
		$op       = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > An end tag whose tag name is one of: "td", "th"
			 */
			case '-TD':
			case '-TH':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( $tag_name ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				$this->generate_implied_end_tags();

				/*
				 * @todo This needs to check if the current node is an HTML element, meaning that
				 *       when SVG and MathML support is added, this needs to differentiate between an
				 *       HTML element of the given name, such as `<center>`, and a foreign element of
				 *       the same given name.
				 */
				if ( ! $this->state->stack_of_open_elements->current_node_is( $tag_name ) ) {
					// @todo Indicate a parse error once it's possible.
				}

				$this->state->stack_of_open_elements->pop_until( $tag_name );
				$this->state->active_formatting_elements->clear_up_to_last_marker();
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_ROW;
				return true;

			/*
			 * > A start tag whose tag name is one of: "caption", "col", "colgroup", "tbody", "td",
			 * > "tfoot", "th", "thead", "tr"
			 */
			case '+CAPTION':
			case '+COL':
			case '+COLGROUP':
			case '+TBODY':
			case '+TD':
			case '+TFOOT':
			case '+TH':
			case '+THEAD':
			case '+TR':
				/*
				 * > Assert: The stack of open elements has a td or th element in table scope.
				 *
				 * Nothing to do here, except to verify in tests that this never appears.
				 */

				$this->close_cell();
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is one of: "body", "caption", "col", "colgroup", "html"
			 */
			case '-BODY':
			case '-CAPTION':
			case '-COL':
			case '-COLGROUP':
			case '-HTML':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > An end tag whose tag name is one of: "table", "tbody", "tfoot", "thead", "tr"
			 */
			case '-TABLE':
			case '-TBODY':
			case '-TFOOT':
			case '-THEAD':
			case '-TR':
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( $tag_name ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}
				$this->close_cell();
				return $this->step( self::REPROCESS_CURRENT_NODE );
		}

		/*
		 * > Anything else
		 * >   Process the token using the rules for the "in body" insertion mode.
		 */
		return $this->step_in_body();
	}

	/**
	 * Parses next element in the 'in select' insertion mode.
	 *
	 * This internal function performs the 'in select' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/multipage/parsing.html#parsing-main-inselect
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_select(): bool {
		$token_name = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( parent::is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$token_name}";

		switch ( $op ) {
			/*
			 * > Any other character token
			 */
			case '#text':
				/*
				 * > A character token that is U+0000 NULL
				 *
				 * If a text node only comprises null bytes then it should be
				 * entirely ignored and should not return to calling code.
				 */
				if ( parent::TEXT_IS_NULL_SEQUENCE === $this->text_node_classification ) {
					// Parse error: ignore the token.
					return $this->step();
				}

				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "html"
			 */
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > A start tag whose tag name is "option"
			 */
			case '+OPTION':
				if ( $this->state->stack_of_open_elements->current_node_is( 'OPTION' ) ) {
					$this->state->stack_of_open_elements->pop();
				}
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A start tag whose tag name is "optgroup"
			 * > A start tag whose tag name is "hr"
			 *
			 * These rules are identical except for the treatment of the self-closing flag and
			 * the subsequent pop of the HR void element, all of which is handled elsewhere in the processor.
			 */
			case '+OPTGROUP':
			case '+HR':
				if ( $this->state->stack_of_open_elements->current_node_is( 'OPTION' ) ) {
					$this->state->stack_of_open_elements->pop();
				}

				if ( $this->state->stack_of_open_elements->current_node_is( 'OPTGROUP' ) ) {
					$this->state->stack_of_open_elements->pop();
				}

				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > An end tag whose tag name is "optgroup"
			 */
			case '-OPTGROUP':
				$current_node = $this->state->stack_of_open_elements->current_node();
				if ( $current_node && 'OPTION' === $current_node->node_name ) {
					foreach ( $this->state->stack_of_open_elements->walk_up( $current_node ) as $parent ) {
						break;
					}
					if ( $parent && 'OPTGROUP' === $parent->node_name ) {
						$this->state->stack_of_open_elements->pop();
					}
				}

				if ( $this->state->stack_of_open_elements->current_node_is( 'OPTGROUP' ) ) {
					$this->state->stack_of_open_elements->pop();
					return true;
				}

				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > An end tag whose tag name is "option"
			 */
			case '-OPTION':
				if ( $this->state->stack_of_open_elements->current_node_is( 'OPTION' ) ) {
					$this->state->stack_of_open_elements->pop();
					return true;
				}

				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > An end tag whose tag name is "select"
			 * > A start tag whose tag name is "select"
			 *
			 * > It just gets treated like an end tag.
			 */
			case '-SELECT':
			case '+SELECT':
				if ( ! $this->state->stack_of_open_elements->has_element_in_select_scope( 'SELECT' ) ) {
					// Parse error: ignore the token.
					return $this->step();
				}
				$this->state->stack_of_open_elements->pop_until( 'SELECT' );
				$this->reset_insertion_mode_appropriately();
				return true;

			/*
			 * > A start tag whose tag name is one of: "input", "keygen", "textarea"
			 *
			 * All three of these tags are considered a parse error when found in this insertion mode.
			 */
			case '+INPUT':
			case '+KEYGEN':
			case '+TEXTAREA':
				if ( ! $this->state->stack_of_open_elements->has_element_in_select_scope( 'SELECT' ) ) {
					// Ignore the token.
					return $this->step();
				}
				$this->state->stack_of_open_elements->pop_until( 'SELECT' );
				$this->reset_insertion_mode_appropriately();
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > A start tag whose tag name is one of: "script", "template"
			 * > An end tag whose tag name is "template"
			 */
			case '+SCRIPT':
			case '+TEMPLATE':
			case '-TEMPLATE':
				return $this->step_in_head();
		}

		/*
		 * > Anything else
		 * >   Parse error: ignore the token.
		 */
		return $this->step();
	}

	/**
	 * Parses next element in the 'in select in table' insertion mode.
	 *
	 * This internal function performs the 'in select in table' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-inselectintable
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_select_in_table(): bool {
		$token_name = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( parent::is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$token_name}";

		switch ( $op ) {
			/*
			 * > A start tag whose tag name is one of: "caption", "table", "tbody", "tfoot", "thead", "tr", "td", "th"
			 */
			case '+CAPTION':
			case '+TABLE':
			case '+TBODY':
			case '+TFOOT':
			case '+THEAD':
			case '+TR':
			case '+TD':
			case '+TH':
				// @todo Indicate a parse error once it's possible.
				$this->state->stack_of_open_elements->pop_until( 'SELECT' );
				$this->reset_insertion_mode_appropriately();
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > An end tag whose tag name is one of: "caption", "table", "tbody", "tfoot", "thead", "tr", "td", "th"
			 */
			case '-CAPTION':
			case '-TABLE':
			case '-TBODY':
			case '-TFOOT':
			case '-THEAD':
			case '-TR':
			case '-TD':
			case '-TH':
				// @todo Indicate a parse error once it's possible.
				if ( ! $this->state->stack_of_open_elements->has_element_in_table_scope( $token_name ) ) {
					return $this->step();
				}
				$this->state->stack_of_open_elements->pop_until( 'SELECT' );
				$this->reset_insertion_mode_appropriately();
				return $this->step( self::REPROCESS_CURRENT_NODE );
		}

		/*
		 * > Anything else
		 */
		return $this->step_in_select();
	}

	/**
	 * Parses next element in the 'in template' insertion mode.
	 *
	 * This internal function performs the 'in template' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-intemplate
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_template(): bool {
		$token_name = $this->get_token_name();
		$token_type = $this->get_token_type();
		$is_closer  = $this->is_tag_closer();
		$op_sigil   = '#tag' === $token_type ? ( $is_closer ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$token_name}";

		switch ( $op ) {
			/*
			 * > A character token
			 * > A comment token
			 * > A DOCTYPE token
			 */
			case '#text':
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
			case 'html':
				return $this->step_in_body();

			/*
			 * > A start tag whose tag name is one of: "base", "basefont", "bgsound", "link",
			 * > "meta", "noframes", "script", "style", "template", "title"
			 * > An end tag whose tag name is "template"
			 */
			case '+BASE':
			case '+BASEFONT':
			case '+BGSOUND':
			case '+LINK':
			case '+META':
			case '+NOFRAMES':
			case '+SCRIPT':
			case '+STYLE':
			case '+TEMPLATE':
			case '+TITLE':
			case '-TEMPLATE':
				return $this->step_in_head();

			/*
			 * > A start tag whose tag name is one of: "caption", "colgroup", "tbody", "tfoot", "thead"
			 */
			case '+CAPTION':
			case '+COLGROUP':
			case '+TBODY':
			case '+TFOOT':
			case '+THEAD':
				array_pop( $this->state->stack_of_template_insertion_modes );
				$this->state->stack_of_template_insertion_modes[] = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
				$this->state->insertion_mode                      = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > A start tag whose tag name is "col"
			 */
			case '+COL':
				array_pop( $this->state->stack_of_template_insertion_modes );
				$this->state->stack_of_template_insertion_modes[] = WP_HTML_Processor_State::INSERTION_MODE_IN_COLUMN_GROUP;
				$this->state->insertion_mode                      = WP_HTML_Processor_State::INSERTION_MODE_IN_COLUMN_GROUP;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > A start tag whose tag name is "tr"
			 */
			case '+TR':
				array_pop( $this->state->stack_of_template_insertion_modes );
				$this->state->stack_of_template_insertion_modes[] = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				$this->state->insertion_mode                      = WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY;
				return $this->step( self::REPROCESS_CURRENT_NODE );

			/*
			 * > A start tag whose tag name is one of: "td", "th"
			 */
			case '+TD':
			case '+TH':
				array_pop( $this->state->stack_of_template_insertion_modes );
				$this->state->stack_of_template_insertion_modes[] = WP_HTML_Processor_State::INSERTION_MODE_IN_ROW;
				$this->state->insertion_mode                      = WP_HTML_Processor_State::INSERTION_MODE_IN_ROW;
				return $this->step( self::REPROCESS_CURRENT_NODE );
		}

		/*
		 * > Any other start tag
		 */
		if ( ! $is_closer ) {
			array_pop( $this->state->stack_of_template_insertion_modes );
			$this->state->stack_of_template_insertion_modes[] = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
			$this->state->insertion_mode                      = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
			return $this->step( self::REPROCESS_CURRENT_NODE );
		}

		/*
		 * > Any other end tag
		 */
		if ( $is_closer ) {
			// Parse error: ignore the token.
			return $this->step();
		}

		/*
		 * > An end-of-file token
		 */
		if ( ! $this->state->stack_of_open_elements->contains( 'TEMPLATE' ) ) {
			// Stop parsing.
			return false;
		}

		// @todo Indicate a parse error once it's possible.
		$this->state->stack_of_open_elements->pop_until( 'TEMPLATE' );
		$this->state->active_formatting_elements->clear_up_to_last_marker();
		array_pop( $this->state->stack_of_template_insertion_modes );
		$this->reset_insertion_mode_appropriately();
		return $this->step( self::REPROCESS_CURRENT_NODE );
	}

	/**
	 * Parses next element in the 'after body' insertion mode.
	 *
	 * This internal function performs the 'after body' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-afterbody
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_after_body(): bool {
		$tag_name   = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A character token that is one of U+0009 CHARACTER TABULATION, U+000A LINE FEED (LF),
			 * >   U+000C FORM FEED (FF), U+000D CARRIAGE RETURN (CR), or U+0020 SPACE
			 *
			 * > Process the token using the rules for the "in body" insertion mode.
			 */
			case '#text':
				if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
					return $this->step_in_body();
				}
				goto after_body_anything_else;
				break;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->bail( 'Content outside of BODY is unsupported.' );
				break;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "html"
			 */
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > An end tag whose tag name is "html"
			 *
			 * > If the parser was created as part of the HTML fragment parsing algorithm,
			 * > this is a parse error; ignore the token. (fragment case)
			 * >
			 * > Otherwise, switch the insertion mode to "after after body".
			 */
			case '-HTML':
				if ( isset( $this->context_node ) ) {
					return $this->step();
				}

				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_AFTER_AFTER_BODY;
				return true;
		}

		/*
		 * > Parse error. Switch the insertion mode to "in body" and reprocess the token.
		 */
		after_body_anything_else:
		$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
		return $this->step( self::REPROCESS_CURRENT_NODE );
	}

	/**
	 * Parses next element in the 'in frameset' insertion mode.
	 *
	 * This internal function performs the 'in frameset' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-inframeset
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_frameset(): bool {
		$tag_name   = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A character token that is one of U+0009 CHARACTER TABULATION, U+000A LINE FEED (LF),
			 * >   U+000C FORM FEED (FF), U+000D CARRIAGE RETURN (CR), or U+0020 SPACE
			 * >
			 * > Insert the character.
			 *
			 * This algorithm effectively strips non-whitespace characters from text and inserts
			 * them under HTML. This is not supported at this time.
			 */
			case '#text':
				if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
					return $this->step_in_body();
				}
				$this->bail( 'Non-whitespace characters cannot be handled in frameset.' );
				break;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "html"
			 */
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > A start tag whose tag name is "frameset"
			 */
			case '+FRAMESET':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > An end tag whose tag name is "frameset"
			 */
			case '-FRAMESET':
				/*
				 * > If the current node is the root html element, then this is a parse error;
				 * > ignore the token. (fragment case)
				 */
				if ( $this->state->stack_of_open_elements->current_node_is( 'HTML' ) ) {
					return $this->step();
				}

				/*
				 * > Otherwise, pop the current node from the stack of open elements.
				 */
				$this->state->stack_of_open_elements->pop();

				/*
				 * > If the parser was not created as part of the HTML fragment parsing algorithm
				 * > (fragment case), and the current node is no longer a frameset element, then
				 * > switch the insertion mode to "after frameset".
				 */
				if ( ! isset( $this->context_node ) && ! $this->state->stack_of_open_elements->current_node_is( 'FRAMESET' ) ) {
					$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_AFTER_FRAMESET;
				}

				return true;

			/*
			 * > A start tag whose tag name is "frame"
			 *
			 * > Insert an HTML element for the token. Immediately pop the
			 * > current node off the stack of open elements.
			 * >
			 * > Acknowledge the token's self-closing flag, if it is set.
			 */
			case '+FRAME':
				$this->insert_html_element( $this->state->current_token );
				$this->state->stack_of_open_elements->pop();
				return true;

			/*
			 * > A start tag whose tag name is "noframes"
			 */
			case '+NOFRAMES':
				return $this->step_in_head();
		}

		// Parse error: ignore the token.
		return $this->step();
	}

	/**
	 * Parses next element in the 'after frameset' insertion mode.
	 *
	 * This internal function performs the 'after frameset' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-afterframeset
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_after_frameset(): bool {
		$tag_name   = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A character token that is one of U+0009 CHARACTER TABULATION, U+000A LINE FEED (LF),
			 * >   U+000C FORM FEED (FF), U+000D CARRIAGE RETURN (CR), or U+0020 SPACE
			 * >
			 * > Insert the character.
			 *
			 * This algorithm effectively strips non-whitespace characters from text and inserts
			 * them under HTML. This is not supported at this time.
			 */
			case '#text':
				if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
					return $this->step_in_body();
				}
				$this->bail( 'Non-whitespace characters cannot be handled in after frameset' );
				break;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->insert_html_element( $this->state->current_token );
				return true;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "html"
			 */
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > An end tag whose tag name is "html"
			 */
			case '-HTML':
				$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_AFTER_AFTER_FRAMESET;
				return true;

			/*
			 * > A start tag whose tag name is "noframes"
			 */
			case '+NOFRAMES':
				return $this->step_in_head();
		}

		// Parse error: ignore the token.
		return $this->step();
	}

	/**
	 * Parses next element in the 'after after body' insertion mode.
	 *
	 * This internal function performs the 'after after body' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#the-after-after-body-insertion-mode
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_after_after_body(): bool {
		$tag_name   = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->bail( 'Content outside of HTML is unsupported.' );
				break;

			/*
			 * > A DOCTYPE token
			 * > A start tag whose tag name is "html"
			 *
			 * > Process the token using the rules for the "in body" insertion mode.
			 */
			case 'html':
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > A character token that is one of U+0009 CHARACTER TABULATION, U+000A LINE FEED (LF),
			 * >   U+000C FORM FEED (FF), U+000D CARRIAGE RETURN (CR), or U+0020 SPACE
			 * >
			 * > Process the token using the rules for the "in body" insertion mode.
			 */
			case '#text':
				if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
					return $this->step_in_body();
				}
				goto after_after_body_anything_else;
				break;
		}

		/*
		 * > Parse error. Switch the insertion mode to "in body" and reprocess the token.
		 */
		after_after_body_anything_else:
		$this->state->insertion_mode = WP_HTML_Processor_State::INSERTION_MODE_IN_BODY;
		return $this->step( self::REPROCESS_CURRENT_NODE );
	}

	/**
	 * Parses next element in the 'after after frameset' insertion mode.
	 *
	 * This internal function performs the 'after after frameset' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#the-after-after-frameset-insertion-mode
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_after_after_frameset(): bool {
		$tag_name   = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$tag_name}";

		switch ( $op ) {
			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->bail( 'Content outside of HTML is unsupported.' );
				break;

			/*
			 * > A DOCTYPE token
			 * > A start tag whose tag name is "html"
			 *
			 * > Process the token using the rules for the "in body" insertion mode.
			 */
			case 'html':
			case '+HTML':
				return $this->step_in_body();

			/*
			 * > A character token that is one of U+0009 CHARACTER TABULATION, U+000A LINE FEED (LF),
			 * >   U+000C FORM FEED (FF), U+000D CARRIAGE RETURN (CR), or U+0020 SPACE
			 * >
			 * > Process the token using the rules for the "in body" insertion mode.
			 *
			 * This algorithm effectively strips non-whitespace characters from text and inserts
			 * them under HTML. This is not supported at this time.
			 */
			case '#text':
				if ( parent::TEXT_IS_WHITESPACE === $this->text_node_classification ) {
					return $this->step_in_body();
				}
				$this->bail( 'Non-whitespace characters cannot be handled in after after frameset.' );
				break;

			/*
			 * > A start tag whose tag name is "noframes"
			 */
			case '+NOFRAMES':
				return $this->step_in_head();
		}

		// Parse error: ignore the token.
		return $this->step();
	}

	/**
	 * Parses next element in the 'in foreign content' insertion mode.
	 *
	 * This internal function performs the 'in foreign content' insertion mode
	 * logic for the generalized WP_HTML_Processor::step() function.
	 *
	 * @since 6.7.0 Stub implementation.
	 *
	 * @throws WP_HTML_Unsupported_Exception When encountering unsupported HTML input.
	 *
	 * @see https://html.spec.whatwg.org/#parsing-main-inforeign
	 * @see WP_HTML_Processor::step
	 *
	 * @return bool Whether an element was found.
	 */
	private function step_in_foreign_content(): bool {
		$tag_name   = $this->get_token_name();
		$token_type = $this->get_token_type();
		$op_sigil   = '#tag' === $token_type ? ( $this->is_tag_closer() ? '-' : '+' ) : '';
		$op         = "{$op_sigil}{$tag_name}";

		/*
		 * > A start tag whose name is "font", if the token has any attributes named "color", "face", or "size"
		 *
		 * This section drawn out above the switch to more easily incorporate
		 * the additional rules based on the presence of the attributes.
		 */
		if (
			'+FONT' === $op &&
			(
				null !== $this->get_attribute( 'color' ) ||
				null !== $this->get_attribute( 'face' ) ||
				null !== $this->get_attribute( 'size' )
			)
		) {
			$op = '+FONT with attributes';
		}

		switch ( $op ) {
			case '#text':
				/*
				 * > A character token that is U+0000 NULL
				 *
				 * This is handled by `get_modifiable_text()`.
				 */

				/*
				 * Whitespace-only text does not affect the frameset-ok flag.
				 * It is probably inter-element whitespace, but it may also
				 * contain character references which decode only to whitespace.
				 */
				if ( parent::TEXT_IS_GENERIC === $this->text_node_classification ) {
					$this->state->frameset_ok = false;
				}

				$this->insert_foreign_element( $this->state->current_token, false );
				return true;

			/*
			 * CDATA sections are alternate wrappers for text content and therefore
			 * ought to follow the same rules as text nodes.
			 */
			case '#cdata-section':
				/*
				 * NULL bytes and whitespace do not change the frameset-ok flag.
				 */
				$current_token        = $this->bookmarks[ $this->state->current_token->bookmark_name ];
				$cdata_content_start  = $current_token->start + 9;
				$cdata_content_length = $current_token->length - 12;
				if ( strspn( $this->html, "\0 \t\n\f\r", $cdata_content_start, $cdata_content_length ) !== $cdata_content_length ) {
					$this->state->frameset_ok = false;
				}

				$this->insert_foreign_element( $this->state->current_token, false );
				return true;

			/*
			 * > A comment token
			 */
			case '#comment':
			case '#funky-comment':
			case '#presumptuous-tag':
				$this->insert_foreign_element( $this->state->current_token, false );
				return true;

			/*
			 * > A DOCTYPE token
			 */
			case 'html':
				// Parse error: ignore the token.
				return $this->step();

			/*
			 * > A start tag whose tag name is "b", "big", "blockquote", "body", "br", "center",
			 * > "code", "dd", "div", "dl", "dt", "em", "embed", "h1", "h2", "h3", "h4", "h5",
			 * > "h6", "head", "hr", "i", "img", "li", "listing", "menu", "meta", "nobr", "ol",
			 * > "p", "pre", "ruby", "s", "small", "span", "strong", "strike", "sub", "sup",
			 * > "table", "tt", "u", "ul", "var"
			 *
			 * > A start tag whose name is "font", if the token has any attributes named "color", "face", or "size"
			 *
			 * > An end tag whose tag name is "br", "p"
			 *
			 * Closing BR tags are always reported by the Tag Processor as opening tags.
			 */
			case '+B':
			case '+BIG':
			case '+BLOCKQUOTE':
			case '+BODY':
			case '+BR':
			case '+CENTER':
			case '+CODE':
			case '+DD':
			case '+DIV':
			case '+DL':
			case '+DT':
			case '+EM':
			case '+EMBED':
			case '+H1':
			case '+H2':
			case '+H3':
			case '+H4':
			case '+H5':
			case '+H6':
			case '+HEAD':
			case '+HR':
			case '+I':
			case '+IMG':
			case '+LI':
			case '+LISTING':
			case '+MENU':
			case '+META':
			case '+NOBR':
			case '+OL':
			case '+P':
			case '+PRE':
			case '+RUBY':
			case '+S':
			case '+SMALL':
			case '+SPAN':
			case '+STRONG':
			case '+STRIKE':
			case '+SUB':
			case '+SUP':
			case '+TABLE':
			case '+TT':
			case '+U':
			case '+UL':
			case '+VAR':
			case '+FONT with attributes':
			case '-BR':
			case '-P':
				// @todo Indicate a parse error once it's possible.
				foreach ( $this->state->stack_of_open_elements->walk_up() as $current_node ) {
					if (
						'math' === $current_node->integration_node_type ||
						'html' === $current_node->integration_node_type ||
						'html' === $current_node->namespace
					) {
						break;
					}

					$this->state->stack_of_open_elements->pop();
				}
				goto in_foreign_content_process_in_current_insertion_mode;
		}

		/*
		 * > Any other start tag
		 */
		if ( ! $this->is_tag_closer() ) {
			$this->insert_foreign_element( $this->state->current_token, false );

			/*
			 * > If the token has its self-closing flag set, then run
			 * > the appropriate steps from the following list:
			 * >
			 * >   ↪ the token's tag name is "script", and the new current node is in the SVG namespace
			 * >         Acknowledge the token's self-closing flag, and then act as
			 * >         described in the steps for a "script" end tag below.
			 * >
			 * >   ↪ Otherwise
			 * >         Pop the current node off the stack of open elements and
			 * >         acknowledge the token's self-closing flag.
			 *
			 * Since the rules for SCRIPT below indicate to pop the element off of the stack of
			 * open elements, which is the same for the Otherwise condition, there's no need to
			 * separate these checks. The difference comes when a parser operates with the scripting
			 * flag enabled, and executes the script, which this parser does not support.
			 */
			if ( $this->state->current_token->has_self_closing_flag ) {
				$this->state->stack_of_open_elements->pop();
			}
			return true;
		}

		/*
		 * > An end tag whose name is "script", if the current node is an SVG script element.
		 */
		if ( $this->is_tag_closer() && 'SCRIPT' === $this->state->current_token->node_name && 'svg' === $this->state->current_token->namespace ) {
			$this->state->stack_of_open_elements->pop();
			return true;
		}

		/*
		 * > Any other end tag
		 */
		if ( $this->is_tag_closer() ) {
			$node = $this->state->stack_of_open_elements->current_node();
			if ( $tag_name !== $node->node_name ) {
				// @todo Indicate a parse error once it's possible.
			}
			in_foreign_content_end_tag_loop:
			if ( $node === $this->state->stack_of_open_elements->at( 1 ) ) {
				return true;
			}

			/*
			 * > If node's tag name, converted to ASCII lowercase, is the same as the tag name
			 * > of the token, pop elements from the stack of open elements until node has
			 * > been popped from the stack, and then return.
			 */
			if ( 0 === strcasecmp( $node->node_name, $tag_name ) ) {
				foreach ( $this->state->stack_of_open_elements->walk_up() as $item ) {
					$this->state->stack_of_open_elements->pop();
					if ( $node === $item ) {
						return true;
					}
				}
			}

			foreach ( $this->state->stack_of_open_elements->walk_up( $node ) as $item ) {
				$node = $item;
				break;
			}

			if ( 'html' !== $node->namespace ) {
				goto in_foreign_content_end_tag_loop;
			}

			in_foreign_content_process_in_current_insertion_mode:
			switch ( $this->state->insertion_mode ) {
				case WP_HTML_Processor_State::INSERTION_MODE_INITIAL:
					return $this->step_initial();

				case WP_HTML_Processor_State::INSERTION_MODE_BEFORE_HTML:
					return $this->step_before_html();

				case WP_HTML_Processor_State::INSERTION_MODE_BEFORE_HEAD:
					return $this->step_before_head();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_HEAD:
					return $this->step_in_head();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_HEAD_NOSCRIPT:
					return $this->step_in_head_noscript();

				case WP_HTML_Processor_State::INSERTION_MODE_AFTER_HEAD:
					return $this->step_after_head();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_BODY:
					return $this->step_in_body();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE:
					return $this->step_in_table();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_TEXT:
					return $this->step_in_table_text();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_CAPTION:
					return $this->step_in_caption();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_COLUMN_GROUP:
					return $this->step_in_column_group();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_TABLE_BODY:
					return $this->step_in_table_body();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_ROW:
					return $this->step_in_row();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_CELL:
					return $this->step_in_cell();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_SELECT:
					return $this->step_in_select();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_SELECT_IN_TABLE:
					return $this->step_in_select_in_table();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_TEMPLATE:
					return $this->step_in_template();

				case WP_HTML_Processor_State::INSERTION_MODE_AFTER_BODY:
					return $this->step_after_body();

				case WP_HTML_Processor_State::INSERTION_MODE_IN_FRAMESET:
					return $this->step_in_frameset();

				case WP_HTML_Processor_State::INSERTION_MODE_AFTER_FRAMESET:
					return $this->step_after_frameset();

				case WP_HTML_Processor_State::INSERTION_MODE_AFTER_AFTER_BODY:
					return $this->step_after_after_body();

				case WP_HTML_Processor_State::INSERTION_MODE_AFTER_AFTER_FRAMESET:
					return $this->step_after_after_frameset();

				// This should be unreachable but PHP doesn't have total type checking on switch.
				default:
					$this->bail( "Unaware of the requested parsing mode: '{$this->state->insertion_mode}'." );
			}
		}

		$this->bail( 'Should not have been able to reach end of IN FOREIGN CONTENT processing. Check HTML API code.' );
		// This unnecessary return prevents tools from inaccurately reporting type errors.
		return false;
	}

	/*
	 * Internal helpers
	 */

	/**
	 * Creates a new bookmark for the currently-matched token and returns the generated name.
	 *
	 * @since 6.4.0
	 * @since 6.5.0 Renamed from bookmark_tag() to bookmark_token().
	 *
	 * @throws Exception When unable to allocate requested bookmark.
	 *
	 * @return string|false Name of created bookmark, or false if unable to create.
	 */
	private function bookmark_token() {
		if ( ! parent::set_bookmark( ++$this->bookmark_counter ) ) {
			$this->last_error = self::ERROR_EXCEEDED_MAX_BOOKMARKS;
			throw new Exception( 'could not allocate bookmark' );
		}

		return "{$this->bookmark_counter}";
	}

	/*
	 * HTML semantic overrides for Tag Processor
	 */

	/**
	 * Indicates the namespace of the current token, or "html" if there is none.
	 *
	 * @return string One of "html", "math", or "svg".
	 */
	public function get_namespace(): string {
		if ( ! isset( $this->current_element ) ) {
			return parent::get_namespace();
		}

		return $this->current_element->token->namespace;
	}

	/**
	 * Returns the uppercase name of the matched tag.
	 *
	 * The semantic rules for HTML specify that certain tags be reprocessed
	 * with a different tag name. Because of this, the tag name presented
	 * by the HTML Processor may differ from the one reported by the HTML
	 * Tag Processor, which doesn't apply these semantic rules.
	 *
	 * Example:
	 *
	 *     $processor = new WP_HTML_Tag_Processor( '<div class="test">Test</div>' );
	 *     $processor->next_tag() === true;
	 *     $processor->get_tag() === 'DIV';
	 *
	 *     $processor->next_tag() === false;
	 *     $processor->get_tag() === null;
	 *
	 * @since 6.4.0
	 *
	 * @return string|null Name of currently matched tag in input HTML, or `null` if none found.
	 */
	public function get_tag(): ?string {
		if ( null !== $this->last_error ) {
			return null;
		}

		if ( $this->is_virtual() ) {
			return $this->current_element->token->node_name;
		}

		$tag_name = parent::get_tag();

		/*
		 * > A start tag whose tag name is "image"
		 * > Change the token's tag name to "img" and reprocess it. (Don't ask.)
		 */
		return ( 'IMAGE' === $tag_name && 'html' === $this->get_namespace() )
			? 'IMG'
			: $tag_name;
	}

	/**
	 * Indicates if the currently matched tag contains the self-closing flag.
	 *
	 * No HTML elements ought to have the self-closing flag and for those, the self-closing
	 * flag will be ignored. For void elements this is benign because they "self close"
	 * automatically. For non-void HTML elements though problems will appear if someone
	 * intends to use a self-closing element in place of that element with an empty body.
	 * For HTML foreign elements and custom elements the self-closing flag determines if
	 * they self-close or not.
	 *
	 * This function does not determine if a tag is self-closing,
	 * but only if the self-closing flag is present in the syntax.
	 *
	 * @since 6.6.0 Subclassed for the HTML Processor.
	 *
	 * @return bool Whether the currently matched tag contains the self-closing flag.
	 */
	public function has_self_closing_flag(): bool {
		return $this->is_virtual() ? false : parent::has_self_closing_flag();
	}

	/**
	 * Returns the node name represented by the token.
	 *
	 * This matches the DOM API value `nodeName`. Some values
	 * are static, such as `#text` for a text node, while others
	 * are dynamically generated from the token itself.
	 *
	 * Dynamic names:
	 *  - Uppercase tag name for tag matches.
	 *  - `html` for DOCTYPE declarations.
	 *
	 * Note that if the Tag Processor is not matched on a token
	 * then this function will return `null`, either because it
	 * hasn't yet found a token or because it reached the end
	 * of the document without matching a token.
	 *
	 * @since 6.6.0 Subclassed for the HTML Processor.
	 *
	 * @return string|null Name of the matched token.
	 */
	public function get_token_name(): ?string {
		return $this->is_virtual()
			? $this->current_element->token->node_name
			: parent::get_token_name();
	}

	/**
	 * Indicates the kind of matched token, if any.
	 *
	 * This differs from `get_token_name()` in that it always
	 * returns a static string indicating the type, whereas
	 * `get_token_name()` may return values derived from the
	 * token itself, such as a tag name or processing
	 * instruction tag.
	 *
	 * Possible values:
	 *  - `#tag` when matched on a tag.
	 *  - `#text` when matched on a text node.
	 *  - `#cdata-section` when matched on a CDATA node.
	 *  - `#comment` when matched on a comment.
	 *  - `#doctype` when matched on a DOCTYPE declaration.
	 *  - `#presumptuous-tag` when matched on an empty tag closer.
	 *  - `#funky-comment` when matched on a funky comment.
	 *
	 * @since 6.6.0 Subclassed for the HTML Processor.
	 *
	 * @return string|null What kind of token is matched, or null.
	 */
	public function get_token_type(): ?string {
		if ( $this->is_virtual() ) {
			/*
			 * This logic comes from the Tag Processor.
			 *
			 * @todo It would be ideal not to repeat this here, but it's not clearly
			 *       better to allow passing a token name to `get_token_type()`.
			 */
			$node_name     = $this->current_element->token->node_name;
			$starting_char = $node_name[0];
			if ( 'A' <= $starting_char && 'Z' >= $starting_char ) {
				return '#tag';
			}

			if ( 'html' === $node_name ) {
				return '#doctype';
			}

			return $node_name;
		}

		retur<HTML><HEAD><TITLE>500-internal server error</TITLE></HEAD><BODY><H1>Error occurred: 500 - internal server error</H1><HR></BODY></HTML>