protected static function get_default_node_fixes() {
		return [
			self::CHARACTERS         => [
				// Nodify anything that requires adjacent text awareness here.
				Node_Fixes\Smart_Maths_Fix::class      => [],
				Node_Fixes\Smart_Diacritics_Fix::class => [],
				Node_Fixes\Smart_Quotes_Fix::class     => [ 'feed' => true ],
				Node_Fixes\Smart_Dashes_Fix::class     => [ 'feed' => true ],
				Node_Fixes\Smart_Ellipses_Fix::class   => [ 'feed' => true ],
				Node_Fixes\Smart_Marks_Fix::class      => [ 'feed' => true ],
			],

			self::SPACING_PRE_WORDS  => [
				// Keep spacing after smart character replacement.
				Node_Fixes\Single_Character_Word_Spacing_Fix::class => [],
				Node_Fixes\Dash_Spacing_Fix::class                  => [],
				Node_Fixes\Unit_Spacing_Fix::class                  => [],
				Node_Fixes\Numbered_Abbreviation_Spacing_Fix::class => [],
				Node_Fixes\French_Punctuation_Spacing_Fix::class    => [],
			],

			self::SPACING_POST_WORDS => [
				// Some final space manipulation.
				Node_Fixes\Dewidow_Fix::class        => [],
				Node_Fixes\Space_Collapse_Fix::class => [],
			],

			self::HTML_INSERTION     => [
				// Everything that requires HTML injection occurs here (functions above assume tag-free content)
				// pay careful attention to functions below for tolerance of injected tags.
				Node_Fixes\Smart_Ordinal_Suffix_Fix::class      => [
					// call before "Style_Numbers_Fix" and "Smart_Fractions_Fix".
					'classes' => [ 'ordinal' ],
				],
				Node_Fixes\Smart_Exponents_Fix::class           => [
					// call before "Style_Numbers_Fix".
				],
				Node_Fixes\Smart_Fractions_Fix::class           => [
					// call before "Style_Numbers_Fix" and after "Smart_Ordinal_Suffix_Fix".
					'classes' => [ 'numerator', 'denominator' ],
				],
				Node_Fixes\Style_Caps_Fix::class                => [
					// Call before "Style_Numbers_Fix".
					'classes' => [ 'caps' ],
				],
				Node_Fixes\Style_Numbers_Fix::class             => [
					// Call after "Smart_Ordinal_Suffix_Fix", "Smart_Exponents_Fix", "Smart_Fractions_Fix", and "Style_Caps_Fix".
					'classes' => [ 'numbers' ],
				],
				Node_Fixes\Style_Ampersands_Fix::class          => [
					'classes' => [ 'amp' ],
				],
				Node_Fixes\Style_Initial_Quotes_Fix::class      => [
					'classes' => [ 'quo', 'dquo' ],
				],
				Node_Fixes\Style_Hanging_Punctuation_Fix::class => [
					'classes' => [ 'push-single', 'push-double', 'pull-single', 'pull-double' ],
				],
			],
		];
	}