<?php

namespace AmpProject\Html;

/**
 * Interface with constants for the different types of attributes.
 *
 * phpcs:disable Generic.Files.LineLength.TooLong
 *
 * @package ampproject/amp-toolbox
 */
interface Attribute
{
    const ABBR                            = 'abbr';
    const ABOUT                           = 'about';
    const ACCEPT                          = 'accept';
    const ACCEPT_CHARSET                  = 'accept-charset';
    const ACCESSKEY                       = 'accesskey';
    const ACCESS_HIDE                     = 'access-hide';
    const ACTION                          = 'action';
    const ACTION_XHR                      = 'action-xhr';
    const ADVANCE_COUNT                   = 'advance-count';
    const ALBUM                           = 'album';
    const ALIGN                           = 'align';
    const ALIGNMENT_BASELINE              = 'alignment-baseline';
    const ALIGN_CONTENT                   = 'align-content';
    const ALIGN_ITEMS                     = 'align-items';
    const ALIGN_SELF                      = 'align-self';
    const ALL                             = 'all';
    const ALLOW                           = 'allow';
    const ALLOWFULLSCREEN                 = 'allowfullscreen';
    const ALLOWPAYMENTREQUEST             = 'allowpaymentrequest';
    const ALLOWTRANSPARENCY               = 'allowtransparency';
    const ALLOW_BLOCKED_END_DATE          = 'allow-blocked-end-date';
    const ALLOW_BLOCKED_RANGES            = 'allow-blocked-ranges';
    const ALLOW_SSR_IMG                   = 'allow-ssr-img';
    const ALPHA                           = 'alpha';
    const ALPHA_RANGE                     = 'alpha-range';
    const ALT                             = 'alt';
    const ALWAYS_SERVE_NPA                = 'alwaysServeNpa';
    const AMP                             = 'amp';
    const AMP4ADS                         = 'amp4ads';
    const AMP4ADS_BOILERPLATE             = 'amp4ads-boilerplate';
    const AMP4ADS_EMOJI                   = self::AMP_EMOJI . '4ads';
    const AMP4ADS_EMOJI_ALT               = self::AMP_EMOJI_ALT . '4ads';
    const AMP4EMAIL                       = 'amp4email';
    const AMP4EMAIL_BOILERPLATE           = 'amp4email-boilerplate';
    const AMP4EMAIL_EMOJI                 = self::AMP_EMOJI . '4email';
    const AMP4EMAIL_EMOJI_ALT             = self::AMP_EMOJI_ALT . '4email';
    const AMPLITUDE                       = 'amplitude';
    const AMP_ACCESS                      = 'amp-access';
    const AMP_ACCESS_BEHAVIOR             = 'amp-access-behavior';
    const AMP_ACCESS_HIDE                 = 'amp-access-hide';
    const AMP_ACCESS_ID                   = 'amp-access-id';
    const AMP_ACCESS_LOADER               = 'amp-access-loader';
    const AMP_ACCESS_LOADING              = 'amp-access-loading';
    const AMP_ACCESS_OFF                  = 'amp-access-off';
    const AMP_ACCESS_ON                   = 'amp-access-on';
    const AMP_ACCESS_SHOW                 = 'amp-access-show';
    const AMP_ACCESS_STYLE                = 'amp-access-style';
    const AMP_ACCESS_TEMPLATE             = 'amp-access-template';
    const AMP_BOILERPLATE                 = 'amp-boilerplate';
    const AMP_CUSTOM                      = 'amp-custom';
    const AMP_CUSTOM_LENGTH_CHECK         = 'amp-custom-length-check';
    const AMP_EMOJI                       = "\xE2\x9A\xA1";
    const AMP_EMOJI_ALT                   = "\xE2\x9A\xA1\xEF\xB8\x8F"; // See https://github.com/ampproject/amphtml/issues/25990.
    const AMP_EXTENSION                   = 'amp-extension';
    const AMP_FX                          = 'amp-fx';
    const AMP_KEYFRAMES                   = 'amp-keyframes';
    const AMP_NESTED_SUBMENU              = 'amp-nested-submenu';
    const AMP_NESTED_SUBMENU_CLOSE        = 'amp-nested-submenu-close';
    const AMP_NESTED_SUBMENU_OPEN         = 'amp-nested-submenu-open';
    const AMP_NOSCRIPT                    = 'amp-noscript';
    const AMP_ONERROR                     = 'amp-onerror';
    const AMP_RUNTIME                     = 'amp-runtime';
    const AMP_SCRIPT_SRC                  = 'amp-script-src';
    const AMP_STORY_DVH_POLYFILL          = 'amp-story-dvh-polyfill';
    const ANCHOR                          = 'anchor';
    const ANIMATE                         = 'animate';
    const ANIMATE_IN                      = 'animate-in';
    const ANIMATE_IN_AFTER                = 'animate-in-after';
    const ANIMATE_IN_DELAY                = 'animate-in-delay';
    const ANIMATE_IN_DURATION             = 'animate-in-duration';
    const ANIMATE_IN_TIMING_FUNCTION      = 'animate-in-timing-function';
    const ANIMATION                       = 'animation';
    const ANIMATION_DELAY                 = 'animation-delay';
    const ANIMATION_DIRECTION             = 'animation-direction';
    const ANIMATION_DURATION              = 'animation-duration';
    const ANIMATION_FILL_MODE             = 'animation-fill-mode';
    const ANIMATION_ITERATION_COUNT       = 'animation-iteration-count';
    const ANIMATION_NAME                  = 'animation-name';
    const ANIMATION_PLAY_STATE            = 'animation-play-state';
    const ANIMATION_TIMING_FUNCTION       = 'animation-timing-function';
    const ANTIALIASING                    = 'antialiasing';
    const APPEARANCE                      = 'appearance';
    const ARABIC_FORM                     = 'arabic-form';
    const ARGUMENTS                       = 'arguments';
    const ARIA_ACTIVEDESCENDANT           = 'aria-activedescendant';
    const ARIA_ATOMIC                     = 'aria-atomic';
    const ARIA_AUTOCOMPLETE               = 'aria-autocomplete';
    const ARIA_BUSY                       = 'aria-busy';
    const ARIA_CHECKED                    = 'aria-checked';
    const ARIA_CONTROLS                   = 'aria-controls';
    const ARIA_CURRENT                    = 'aria-current';
    const ARIA_DESCRIBEDBY                = 'aria-describedby';
    const ARIA_DISABLED                   = 'aria-disabled';
    const ARIA_DROPEFFECT                 = 'aria-dropeffect';
    const ARIA_EXPANDED                   = 'aria-expanded';
    const ARIA_FLOWTO                     = 'aria-flowto';
    const ARIA_GRABBED                    = 'aria-grabbed';
    const ARIA_HASPOPUP                   = 'aria-haspopup';
    const ARIA_HIDDEN                     = 'aria-hidden';
    const ARIA_INVALID                    = 'aria-invalid';
    const ARIA_LABEL                      = 'aria-label';
    const ARIA_LABELLEDBY                 = 'aria-labelledby';
    const ARIA_LEVEL                      = 'aria-level';
    const ARIA_LIVE                       = 'aria-live';
    const ARIA_MODAL                      = 'aria-modal';
    const ARIA_MULTILINE                  = 'aria-multiline';
    const ARIA_MULTISELECTABLE            = 'aria-multiselectable';
    const ARIA_ORIENTATION                = 'aria-orientation';
    const ARIA_OWNS                       = 'aria-owns';
    const ARIA_POSINSET                   = 'aria-posinset';
    const ARIA_PRESSED                    = 'aria-pressed';
    const ARIA_READONLY                   = 'aria-readonly';
    const ARIA_RELEVANT                   = 'aria-relevant';
    const ARIA_REQUIRED                   = 'aria-required';
    const ARIA_SELECTED                   = 'aria-selected';
    const ARIA_SETSIZE                    = 'aria-setsize';
    const ARIA_SORT                       = 'aria-sort';
    const ARIA_VALUEMAX                   = 'aria-valuemax';
    const ARIA_VALUEMIN                   = 'aria-valuemin';
    const ARIA_VALUENOW                   = 'aria-valuenow';
    const ARIA_VALUETEXT                  = 'aria-valuetext';
    const ARROWS                          = 'arrows';
    const ARTIST                          = 'artist';
    const ARTWORK                         = 'artwork';
    const ASPECT_RATIO                    = 'aspect-ratio';
    const ASPECT_RATIO_HEIGHT             = 'aspect-ratio-height';
    const ASPECT_RATIO_WIDTH              = 'aspect-ratio-width';
    const ASYNC                           = 'async';
    const AS_                             = 'as'; // Underscore needed because 'as' is a PHP keyword.
    const ATTRIBUTION                     = 'attribution';
    const ATTRIBUTIONDESTINATION          = 'attributiondestination';
    const ATTRIBUTIONEXPIRY               = 'attributionexpiry';
    const ATTRIBUTIONREPORTTO             = 'attributionreportto';
    const ATTRIBUTIONSOURCEEVENTID        = 'attributionsourceeventid';
    const ATTRIBUTIONSOURCEID             = 'attributionsourceid';
    const AUTOCOMPLETE                    = 'autocomplete';
    const AUTOEXPAND                      = 'autoexpand';
    const AUTOFOCUS                       = 'autofocus';
    const AUTOPLAY                        = 'autoplay';
    const AUTOROTATE                      = 'autorotate';
    const AUTOSCROLL                      = 'autoscroll';
    const AUTO_ADVANCE                    = 'auto-advance';
    const AUTO_ADVANCE_AFTER              = 'auto-advance-after';
    const AUTO_ADVANCE_COUNT              = 'auto-advance-count';
    const AUTO_ADVANCE_INTERVAL           = 'auto-advance-interval';
    const AUTO_ADVANCE_LOOPS              = 'auto-advance-loops';
    const AUTO_RESIZE                     = 'auto-resize';
    const AZIMUTH                         = 'azimuth';
    const BACKFACE_VISIBILITY             = 'backface-visibility';
    const BACKGROUND                      = 'background';
    const BACKGROUND_ATTACHMENT           = 'background-attachment';
    const BACKGROUND_AUDIO                = 'background-audio';
    const BACKGROUND_BLEND_MODE           = 'background-blend-mode';
    const BACKGROUND_CLIP                 = 'background-clip';
    const BACKGROUND_COLOR                = 'background-color';
    const BACKGROUND_IMAGE                = 'background-image';
    const BACKGROUND_ORIGIN               = 'background-origin';
    const BACKGROUND_POSITION             = 'background-position';
    const BACKGROUND_REPEAT               = 'background-repeat';
    const BACKGROUND_SIZE                 = 'background-size';
    const BASEFREQUENCY                   = 'basefrequency';
    const BASELINE_SHIFT                  = 'baseline-shift';
    const BETA_RANGE                      = 'beta-range';
    const BGCOLOR                         = 'bgcolor';
    const BIAS                            = 'bias';
    const BIGGEST_UNIT                    = 'biggest-unit';
    const BINDING                         = 'binding';
    const BLOCK_RTC                       = 'blockRtc';
    const BLOCKED                         = 'blocked';
    const BORDER                          = 'border';
    const BORDER_BOTTOM                   = 'border-bottom';
    const BORDER_BOTTOM_COLOR             = 'border-bottom-color';
    const BORDER_BOTTOM_LEFT_RADIUS       = 'border-bottom-left-radius';
    const BORDER_BOTTOM_RIGHT_RADIUS      = 'border-bottom-right-radius';
    const BORDER_BOTTOM_STYLE             = 'border-bottom-style';
    const BORDER_BOTTOM_WIDTH             = 'border-bottom-width';
    const BORDER_COLLAPSE                 = 'border-collapse';
    const BORDER_COLOR                    = 'border-color';
    const BORDER_IMAGE                    = 'border-image';
    const BORDER_IMAGE_OUTSET             = 'border-image-outset';
    const BORDER_IMAGE_REPEAT             = 'border-image-repeat';
    const BORDER_IMAGE_SLICE              = 'border-image-slice';
    const BORDER_IMAGE_SOURCE             = 'border-image-source';
    const BORDER_IMAGE_WIDTH              = 'border-image-width';
    const BORDER_LEFT                     = 'border-left';
    const BORDER_LEFT_COLOR               = 'border-left-color';
    const BORDER_LEFT_STYLE               = 'border-left-style';
    const BORDER_LEFT_WIDTH               = 'border-left-width';
    const BORDER_RADIUS                   = 'border-radius';
    const BORDER_RIGHT                    = 'border-right';
    const BORDER_RIGHT_COLOR              = 'border-right-color';
    const BORDER_RIGHT_STYLE              = 'border-right-style';
    const BORDER_RIGHT_WIDTH              = 'border-right-width';
    const BORDER_SPACING                  = 'border-spacing';
    const BORDER_STYLE                    = 'border-style';
    const BORDER_TOP                      = 'border-top';
    const BORDER_TOP_COLOR                = 'border-top-color';
    const BORDER_TOP_LEFT_RADIUS          = 'border-top-left-radius';
    const BORDER_TOP_RIGHT_RADIUS         = 'border-top-right-radius';
    const BORDER_TOP_STYLE                = 'border-top-style';
    const BORDER_TOP_WIDTH                = 'border-top-width';
    const BORDER_WIDTH                    = 'border-width';
    const BOTTOM                          = 'bottom';
    const BOX_DECORATION_BREAK            = 'box-decoration-break';
    const BOX_SHADOW                      = 'box-shadow';
    const BOX_SIZING                      = 'box-sizing';
    const BREAK_AFTER                     = 'break-after';
    const BREAK_BEFORE                    = 'break-before';
    const BREAK_INSIDE                    = 'break-inside';
    const CACHE                           = 'cache';
    const CAPTION_SIDE                    = 'caption-side';
    const CAPTIONS_ID                     = 'captions-id';
    const CAPTURE                         = 'capture';
    const CARET_COLOR                     = 'caret-color';
    const CELLPADDING                     = 'cellpadding';
    const CELLSPACING                     = 'cellspacing';
    const CHARSET                         = 'charset';
    const CHECKED                         = 'checked';
    const CHIP_STYLE                      = 'chip-style';
    const CIPHERTEXT                      = 'ciphertext';
    const CITE                            = 'cite';
    const CLASS_                          = 'class'; // Underscore needed because 'class' is a PHP keyword.
    const CLEAR                           = 'clear';
    const CLEARCOLOR                      = 'clearcolor';
    const CLIP                            = 'clip';
    const CLIPPATHUNITS                   = 'clippathunits';
    const CLIP_PATH                       = 'clip-path';
    const CLIP_RULE                       = 'clip-rule';
    const CLOSE_BUTTON                    = 'close-button';
    const COLOR                           = 'color';
    const COLOR_ADJUST                    = 'color-adjust';
    const COLOR_INTERPOLATION             = 'color-interpolation';
    const COLOR_INTERPOLATION_FILTERS     = 'color-interpolation-filters';
    const COLOR_PROFILE                   = 'color-profile';
    const COLOR_RENDERING                 = 'color-rendering';
    const COLS                            = 'cols';
    const COLSPAN                         = 'colspan';
    const COLUMNS                         = 'columns';
    const COLUMN_COUNT                    = 'column-count';
    const COLUMN_FILL                     = 'column-fill';
    const COLUMN_GAP                      = 'column-gap';
    const COLUMN_RULE                     = 'column-rule';
    const COLUMN_RULE_COLOR               = 'column-rule-color';
    const COLUMN_RULE_STYLE               = 'column-rule-style';
    const COLUMN_RULE_WIDTH               = 'column-rule-width';
    const COLUMN_SPAN                     = 'column-span';
    const COLUMN_WIDTH                    = 'column-width';
    const CONFIG                          = 'config';
    const CONTENT                         = 'content';
    const CONTENTSCRIPTTYPE               = 'contentscripttype';
    const CONTENTSTYLETYPE                = 'contentstyletype';
    const CONTROLS                        = 'controls';
    const CONTROLSLIST                    = 'controlslist';
    const CONVERSIONDESTINATION           = 'conversiondestination';
    const COUNT_UP                        = 'count-up';
    const COUNTER_INCREMENT               = 'counter-increment';
    const COUNTER_RESET                   = 'counter-reset';
    const CREDENTIALS                     = 'credentials';
    const CROSSORIGIN                     = 'crossorigin';
    const CRYPTOKEYS                      = 'cryptokeys';
    const CTA_ACCENT_COLOR                = 'cta-accent-color';
    const CTA_ACCENT_ELEMENT              = 'cta-accent-element';
    const CTA_IMAGE                       = 'cta-image';
    const CTA_IMAGE_2                     = 'cta-image-2';
    const CTA_TEXT                        = 'cta-text';
    const CURSOR                          = 'cursor';
    const CUSTOM_ELEMENT                  = 'custom-element';
    const CUSTOM_REDIRECT_DOMAIN          = 'custom-redirect-domain';
    const CUSTOM_TEMPLATE                 = 'custom-template';
    const CUSTOM_TRACKING_ID              = 'custom-tracking-id';
    const CUSTOM_VALIDATION_REPORTING     = 'custom-validation-reporting';
    const CUTOFF                          = 'cutoff';
    const CX                              = 'cx';
    const CY                              = 'cy';
    const D                               = 'd';
    const DATA                            = 'data';
    const DATATYPE                        = 'datatype';
    const DATE                            = 'date';
    const DATES                           = 'dates';
    const DATETIME                        = 'datetime';
    const DATE_TEMPLATE                   = 'date-template';
    const DAY_SIZE                        = 'day-size';
    const DECODING                        = 'decoding';
    const DEEP_PARSING                    = 'deep-parsing';
    const DEFAULT_                        = 'default'; // Underscore needed because 'default' is a PHP keyword.
    const DEFER                           = 'defer';
    const DELAY                           = 'delay';
    const DIFFABLE                        = 'diffable';
    const DIFFUSECONSTANT                 = 'diffuseconstant';
    const DIR                             = 'dir';
    const DIRECTION                       = 'direction';
    const DISABLED                        = 'disabled';
    const DISABLEREMOTEPLAYBACK           = 'disableremoteplayback';
    const DISABLE_DOUBLE_TAP              = 'disable-double-tap';
    const DISABLE_HINT_REAPPEAR           = 'disable-hint-reappear';
    const DISABLE_INLINE_WIDTH            = 'disable-inline-width';
    const DISABLE_SESSION_STATES          = 'disable-session-states';
    const DISPLAY                         = 'display';
    const DISPLAY_IN                      = 'display-in';
    const DIVISOR                         = 'divisor';
    const DOCK                            = 'dock';
    const DOMINANT_BASELINE               = 'dominant-baseline';
    const DOTS                            = 'dots';
    const DOWNLOAD                        = 'download';
    const DRAGGABLE                       = 'draggable';
    const DURATION                        = 'duration';
    const DX                              = 'dx';
    const DY                              = 'dy';
    const EDGEMODE                        = 'edgemode';
    const ELEVATION                       = 'elevation';
    const EMPTY_CELLS                     = 'empty-cells';
    const ENABLEZOOM                      = 'enablezoom';
    const ENABLE_BACKGROUND               = 'enable-background';
    const ENCRYPTED                       = 'encrypted';
    const ENCTYPE                         = 'enctype';
    const ENDPOINT                        = 'endpoint';
    const END_DATE                        = 'end-date';
    const END_INPUT_SELECTOR              = 'end-input-selector';
    const ENTERKEYHINT                    = 'enterkeyhint';
    const ENTITY                          = 'entity';
    const ENTITY_LOGO_SRC                 = 'entity-logo-src';
    const ENTITY_URL                      = 'entity-url';
    const EXCLUDED_DOMAINS                = 'excluded-domains';
    const EXCLUSIVE_LINKS                 = 'exclusive-links';
    const EXECUTE                         = 'execute';
    const EXPANDED                        = 'expanded';
    const EXPAND_SINGLE_SECTION           = 'expand-single-section';
    const EXPONENT                        = 'exponent';
    const EXPRESSION                      = 'expression';
    const EXTERNALRESOURCESREQUIRED       = 'externalresourcesrequired';
    const EXTRA_SPACE                     = 'extra-space';
    const FALLBACK                        = 'fallback';
    const FETCH_ERROR                     = 'fetch-error';
    const FETCHPRIORITY                   = 'fetchpriority';
    const FILL                            = 'fill';
    const FILL_OPACITY                    = 'fill-opacity';
    const FILL_RULE                       = 'fill-rule';
    const FILTER                          = 'filter';
    const FILTERRES                       = 'filterres';
    const FILTERUNITS                     = 'filterunits';
    const FILTER_EXPR                     = 'filter-expr';
    const FILTER_VALUE                    = 'filter-value';
    const FIRST                           = 'first';
    const FIRST_DAY_OF_WEEK               = 'first-day-of-week';
    const FLEX                            = 'flex';
    const FLEX_BASIS                      = 'flex-basis';
    const FLEX_DIRECTION                  = 'flex-direction';
    const FLEX_FLOW                       = 'flex-flow';
    const FLEX_GROW                       = 'flex-grow';
    const FLEX_SHRINK                     = 'flex-shrink';
    const FLEX_WRAP                       = 'flex-wrap';
    const FLOAT                           = 'float';
    const FLOOD_COLOR                     = 'flood-color';
    const FLOOD_OPACITY                   = 'flood-opacity';
    const FOCUSABLE                       = 'focusable';
    const FONT                            = 'font';
    const FONT_FAMILY                     = 'font-family';
    const FONT_FEATURE_SETTINGS           = 'font-feature-settings';
    const FONT_KERNING                    = 'font-kerning';
    const FONT_LANGUAGE_OVERRIDE          = 'font-language-override';
    const FONT_SIZE                       = 'font-size';
    const FONT_SIZE_ADJUST                = 'font-size-adjust';
    const FONT_STRETCH                    = 'font-stretch';
    const FONT_STYLE                      = 'font-style';
    const FONT_SYNTHESIS                  = 'font-synthesis';
    const FONT_VARIANT                    = 'font-variant';
    const FONT_VARIANT_ALTERNATES         = 'font-variant-alternates';
    const FONT_VARIANT_CAPS               = 'font-variant-caps';
    const FONT_VARIANT_EAST_ASIAN         = 'font-variant-east-asian';
    const FONT_VARIANT_LIGATURES          = 'font-variant-ligatures';
    const FONT_VARIANT_NUMERIC            = 'font-variant-numeric';
    const FONT_VARIANT_POSITION           = 'font-variant-position';
    const FONT_VARIATION_SETTINGS         = 'font-variation-settings';
    const FONT_WEIGHT                     = 'font-weight';
    const FOOTER                          = 'footer';
    const FORM                            = 'form';
    const FORMAT                          = 'format';
    const FOR_                            = 'for'; // Underscore needed because 'for' is a PHP keyword.
    const FR                              = 'fr';
    const FRAMEBORDER                     = 'frameborder';
    const FROM                            = 'from';
    const FULLSCREEN                      = 'fullscreen';
    const FX                              = 'fx';
    const FY                              = 'fy';
    const G1                              = 'g1';
    const G2                              = 'g2';
    const GAMMA_RANGE                     = 'gamma-range';
    const GAP                             = 'gap';
    const GLYPHREF                        = 'glyphref';
    const GLYPH_NAME                      = 'glyph-name';
    const GLYPH_ORIENTATION_HORIZONTAL    = 'glyph-orientation-horizontal';
    const GLYPH_ORIENTATION_VERTICAL      = 'glyph-orientation-vertical';
    const GRADIENTTRANSFORM               = 'gradienttransform';
    const GRADIENTUNITS                   = 'gradientunits';
    const GRID                            = 'grid';
    const GRID_AREA                       = 'grid-area';
    const GRID_AUTO_COLUMNS               = 'grid-auto-columns';
    const GRID_AUTO_FLOW                  = 'grid-auto-flow';
    const GRID_AUTO_ROWS                  = 'grid-auto-rows';
    const GRID_COLUMN                     = 'grid-column';
    const GRID_COLUMN_END                 = 'grid-column-end';
    const GRID_COLUMN_GAP                 = 'grid-column-gap';
    const GRID_COLUMN_START               = 'grid-column-start';
    const GRID_GAP                        = 'grid-gap';
    const GRID_ROW                        = 'grid-row';
    const GRID_ROW_END                    = 'grid-row-end';
    const GRID_ROW_GAP                    = 'grid-row-gap';
    const GRID_ROW_START                  = 'grid-row-start';
    const GRID_TEMPLATE                   = 'grid-template';
    const GRID_TEMPLATE_AREAS             = 'grid-template-areas';
    const GRID_TEMPLATE_COLUMNS           = 'grid-template-columns';
    const GRID_TEMPLATE_ROWS              = 'grid-template-rows';
    const GTAG_ID                         = 'gtag-id';
    const HANGING_PUNCTUATION             = 'hanging-punctuation';
    const HEADERS                         = 'headers';
    const HEADING_END                     = 'heading-end';
    const HEADING_START                   = 'heading-start';
    const HEIGHT                          = 'height';
    const HEIGHTS                         = 'heights';
    const HELPER_IFRAME_URL               = 'helper-iframe-url';
    const HIDDEN                          = 'hidden';
    const HIDE_KEYBOARD_SHORTCUTS_PANEL   = 'hide-keyboard-shortcuts-panel';
    const HIGH                            = 'high';
    const HIGHLIGHTED                     = 'highlighted';
    const HIGHLIGHT_USER_ENTRY            = 'highlight-user-entry';
    const HORIZONTAL                      = 'horizontal';
    const HORIZ_ADV_X                     = 'horiz-adv-x';
    const HOST_SERVICE                    = 'host-service';
    const HREF                            = 'href';
    const HREFLANG                        = 'hreflang';
    const HSPACE                          = 'hspace';
    const HTML                            = 'html';
    const HTTP_EQUIV                      = 'http-equiv';
    const HYPHENS                         = 'hyphens';
    const ID                              = 'id';
    const IMAGESIZES                      = 'imagesizes';
    const IMAGESRCSET                     = 'imagesrcset';
    const IMAGE_ORIENTATION               = 'image-orientation';
    const IMAGE_RENDERING                 = 'image-rendering';
    const IMAGE_RESOLUTION                = 'image-resolution';
    const IMPLEMENTS_MEDIA_SESSION        = 'implements-media-session';
    const IMPLEMENTS_ROTATE_TO_FULLSCREEN = 'implements-rotate-to-fullscreen';
    const IMPORTANCE                      = 'importance';
    const IMPRESSIONDATA                  = 'impressiondata';
    const IMPRESSIONEXPIRY                = 'impressionexpiry';
    const IN                              = 'in';
    const IN2                             = 'in2';
    const INFO_TEMPLATE                   = 'info-template';
    const INITIAL_SCALE                   = 'initial-scale';
    const INITIAL_SLIDER_POSITION         = 'initial-slider-position';
    const INITIAL_X                       = 'initial-x';
    const INITIAL_Y                       = 'initial-y';
    const INLINE                          = 'inline';
    const INLINE_SIZE                     = 'inline-size';
    const INLIST                          = 'inlist';
    const INPUTMODE                       = 'inputmode';
    const INPUT_SELECTOR                  = 'input-selector';
    const INSET                           = 'inset';
    const INTEGRITY                       = 'integrity';
    const INTERACTIVE                     = 'interactive';
    const INTERCEPT                       = 'intercept';
    const INTERSECTION_RATIOS             = 'intersection-ratios';
    const INTRINSICSIZE                   = 'intrinsicsize';
    const ISMAP                           = 'ismap';
    const ISOLATION                       = 'isolation';
    const ITEMID                          = 'itemid';
    const ITEMPROP                        = 'itemprop';
    const ITEMREF                         = 'itemref';
    const ITEMS                           = 'items';
    const ITEMSCOPE                       = 'itemscope';
    const ITEMTYPE                        = 'itemtype';
    const I_AMPHTML_BINDING               = 'i-amphtml-binding';
    const I_AMPHTML_DISABLE_AR            = 'i-amphtml-disable-ar';
    const I_AMPHTML_LAYOUT                = 'i-amphtml-layout';
    const I_AMPHTML_NO_BOILERPLATE        = 'i-amphtml-no-boilerplate';
    const I_AMPHTML_SSR                   = 'i-amphtml-ssr';
    const I_AMPHTML_VERSION               = 'i-amphtml-version';
    const I_AMP_ACCESS_ID                 = 'i-amp-access-id';
    const JSON                            = 'json';
    const JUSTIFY_CONTENT                 = 'justify-content';
    const JUSTIFY_ITEMS                   = 'justify-items';
    const JUSTIFY_SELF                    = 'justify-self';
    const K                               = 'k';
    const K1                              = 'k1';
    const K2                              = 'k2';
    const K3                              = 'k3';
    const K4                              = 'k4';
    const KERNELMATRIX                    = 'kernelmatrix';
    const KERNELUNITLENGTH                = 'kernelunitlength';
    const KERNING                         = 'kerning';
    const KEY                             = 'key';
    const KEYBOARD_SELECT_MODE            = 'keyboard-select-mode';
    const KIND                            = 'kind';
    const LABEL                           = 'label';
    const LANG                            = 'lang';
    const LAYOUT                          = 'layout';
    const LEFT                            = 'left';
    const LENGTHADJUST                    = 'lengthadjust';
    const LETTER_SPACING                  = 'letter-spacing';
    const LIGHTBOX                        = 'lightbox';
    const LIGHTBOX_EXCLUDE                = 'lightbox-exclude';
    const LIGHTBOX_THUMBNAIL_ID           = 'lightbox-thumbnail-id';
    const LIGHTING_COLOR                  = 'lighting-color';
    const LIMITINGCONEANGLE               = 'limitingconeangle';
    const LINE_BREAK                      = 'line-break';
    const LINE_HEIGHT                     = 'line-height';
    const LINKMATE                        = 'linkmate';
    const LINK_ATTRIBUTE                  = 'link-attribute';
    const LINK_SELECTOR                   = 'link-selector';
    const LIST_                           = 'list'; // Underscore needed because 'list' is a PHP keyword.
    const LIST_STYLE                      = 'list-style';
    const LIST_STYLE_IMAGE                = 'list-style-image';
    const LIST_STYLE_POSITION             = 'list-style-position';
    const LIST_STYLE_TYPE                 = 'list-style-type';
    const LIVE_STORY                      = 'live-story';
    const LIVE_STORY_DISABLED             = 'live-story-disabled';
    const LOADING                         = 'loading';
    const LOAD_MORE                       = 'load-more';
    const LOAD_MORE_BOOKMARK              = 'load-more-bookmark';
    const LOAD_MORE_BUTTON                = 'load-more-button';
    const LOAD_MORE_CLICKABLE             = 'load-more-clickable';
    const LOAD_MORE_END                   = 'load-more-end';
    const LOAD_MORE_FAILED                = 'load-more-failed';
    const LOAD_MORE_LOADING               = 'load-more-loading';
    const LOCALE                          = 'locale';
    const LOCK_BOUNDS                     = 'lock-bounds';
    const LONGDESC                        = 'longdesc';
    const LOOP                            = 'loop';
    const LOW                             = 'low';
    const MARGIN                          = 'margin';
    const MARGIN_BOTTOM                   = 'margin-bottom';
    const MARGIN_LEFT                     = 'margin-left';
    const MARGIN_RIGHT                    = 'margin-right';
    const MARGIN_TOP                      = 'margin-top';
    const MARKER                          = 'marker';
    const MARKERHEIGHT                    = 'markerheight';
    const MARKERUNITS                     = 'markerunits';
    const MARKERWIDTH                     = 'markerwidth';
    const MARKER_END                      = 'marker-end';
    const MARKER_MID                      = 'marker-mid';
    const MARKER_START                    = 'marker-start';
    const MASK                            = 'mask';
    const MASKCONTENTUNITS                = 'maskcontentunits';
    const MASKUNITS                       = 'maskunits';
    const MASK_OUTPUT                     = 'mask-output';
    const MASK_TRIM_ZEROS                 = 'mask-trim-zeros';
    const MAX                             = 'max';
    const MAXIMUM_NIGHTS                  = 'maximum-nights';
    const MAXLENGTH                       = 'maxlength';
    const MAXPIXELRATIO                   = 'maxpixelratio';
    const MAX_AGE                         = 'max-age';
    const MAX_ENTRIES                     = 'max-entries';
    const MAX_FONT_SIZE                   = 'max-font-size';
    const MAX_HEIGHT                      = 'max-height';
    const MAX_ITEM_WIDTH                  = 'max-item-width';
    const MAX_ITEMS                       = 'max-items';
    const MAX_PAGES                       = 'max-pages';
    const MAX_SCALE                       = 'max-scale';
    const MAX_VISIBLE_COUNT               = 'max-visible-count';
    const MAX_WIDTH                       = 'max-width';
    const MEDIA                           = 'media';
    const METHOD                          = 'method';
    const MIN                             = 'min';
    const MINIMUM_NIGHTS                  = 'minimum-nights';
    const MINLENGTH                       = 'minlength';
    const MIN_CHARACTERS                  = 'min-characters';
    const MIN_FONT_SIZE                   = 'min-font-size';
    const MIN_HEIGHT                      = 'min-height';
    const MIN_ITEM_WIDTH                  = 'min-item-width';
    const MIN_VISIBLE_COUNT               = 'min-visible-count';
    const MIN_WIDTH                       = 'min-width';
    const MIXED_LENGTH                    = 'mixed-length';
    const MIX_BLEND_MODE                  = 'mix-blend-mode';
    const MODE                            = 'mode';
    const MONTH_FORMAT                    = 'month-format';
    const MULTIPLE                        = 'multiple';
    const MUTED                           = 'muted';
    const NAME                            = 'name';
    const NEXT_PAGE_HIDE                  = 'next-page-hide';
    const NEXT_PAGE_NO_AD                 = 'next-page-no-ad';
    const NEXT_PAGE_REPLACE               = 'next-page-replace';
    const NOAUDIO                         = 'noaudio';
    const NOAUTOPLAY                      = 'noautoplay';
    const NODOM                           = 'nodom';
    const NOLOADING                       = 'noloading';
    const NOMODULE                        = 'nomodule';
    const NONCE                           = 'nonce';
    const NOVALIDATE                      = 'novalidate';
    const NO_FALLBACK                     = 'no-fallback';
    const NO_VERIFY                       = 'no-verify';
    const NRTV_ACCOUNT_NAME               = 'nrtv-account-name';
    const NUMBER_OF_MONTHS                = 'number-of-months';
    const NUMOCTAVES                      = 'numoctaves';
    const OBJECT_FIT                      = 'object-fit';
    const OBJECT_POSITION                 = 'object-position';
    const OFFSET                          = 'offset';
    const OFFSET_DISTANCE                 = 'offset-distance';
    const OFFSET_SECONDS                  = 'offset-seconds';
    const ON                              = 'on';
    const ONCE                            = 'once';
    const ON_ERROR_ADD_CLASS              = 'on-error-add-class';
    const ON_ERROR_REMOVE_CLASS           = 'on-error-remove-class';
    const ON_LOAD_ADD_CLASS               = 'on-load-add-class';
    const ON_LOAD_REMOVE_CLASS            = 'on-load-remove-class';
    const OPACITY                         = 'opacity';
    const OPEN                            = 'open';
    const OPEN_AFTER_CLEAR                = 'open-after-clear';
    const OPEN_AFTER_SELECT               = 'open-after-select';
    const OPEN_BUTTON                     = 'open-button';
    const OPERATOR                        = 'operator';
    const OPTIMUM                         = 'optimum';
    const OPTION                          = 'option';
    const OPTION_1_CONFETTI               = 'option-1-confetti';
    const OPTION_1_CORRECT                = 'option-1-correct';
    const OPTION_1_IMAGE                  = 'option-1-image';
    const OPTION_1_IMAGE_ALT              = 'option-1-image-alt';
    const OPTION_1_RESULTS_CATEGORY       = 'option-1-results-category';
    const OPTION_1_RESULTS_THRESHOLD      = 'option-1-results-threshold';
    const OPTION_1_TEXT                   = 'option-1-text';
    const OPTION_2_CONFETTI               = 'option-2-confetti';
    const OPTION_2_CORRECT                = 'option-2-correct';
    const OPTION_2_IMAGE                  = 'option-2-image';
    const OPTION_2_IMAGE_ALT              = 'option-2-image-alt';
    const OPTION_2_RESULTS_CATEGORY       = 'option-2-results-category';
    const OPTION_2_RESULTS_THRESHOLD      = 'option-2-results-threshold';
    const OPTION_2_TEXT                   = 'option-2-text';
    const OPTION_3_CONFETTI               = 'option-3-confetti';
    const OPTION_3_CORRECT                = 'option-3-correct';
    const OPTION_3_IMAGE                  = 'option-3-image';
    const OPTION_3_IMAGE_ALT              = 'option-3-image-alt';
    const OPTION_3_RESULTS_CATEGORY       = 'option-3-results-category';
    const OPTION_3_RESULTS_THRESHOLD      = 'option-3-results-threshold';
    const OPTION_3_TEXT                   = 'option-3-text';
    const OPTION_4_CONFETTI               = 'option-4-confetti';
    const OPTION_4_CORRECT                = 'option-4-correct';
    const OPTION_4_IMAGE                  = 'option-4-image';
    const OPTION_4_IMAGE_ALT              = 'option-4-image-alt';
    const OPTION_4_RESULTS_CATEGORY       = 'option-4-results-category';
    const OPTION_4_RESULTS_THRESHOLD      = 'option-4-results-threshold';
    const OPTION_4_TEXT                   = 'option-4-text';
    const ORDER                           = 'order';
    const ORIENT                          = 'orient';
    const ORIENTATION                     = 'orientation';
    const ORPHANS                         = 'orphans';
    const OUTLINE                         = 'outline';
    const OUTLINE_COLOR                   = 'outline-color';
    const OUTLINE_OFFSET                  = 'outline-offset';
    const OUTLINE_STYLE                   = 'outline-style';
    const OUTLINE_WIDTH                   = 'outline-width';
    const OUTSET_ARROWS                   = 'outset-arrows';
    const OVERFLOW                        = 'overflow';
    const OVERFLOW_STYLE                  = 'overflow-style';
    const OVERFLOW_WRAP                   = 'overflow-wrap';
    const OVERFLOW_X                      = 'overflow-x';
    const OVERFLOW_Y                      = 'overflow-y';
    const OVERRIDABLE                     = 'overridable';
    const PADDING                         = 'padding';
    const PADDING_BOTTOM                  = 'padding-bottom';
    const PADDING_LEFT                    = 'padding-left';
    const PADDING_RIGHT                   = 'padding-right';
    const PADDING_TOP                     = 'padding-top';
    const PAGE_BREAK_AFTER                = 'page-break-after';
    const PAGE_BREAK_BEFORE               = 'page-break-before';
    const PAGE_BREAK_INSIDE               = 'page-break-inside';
    const PAGINATION                      = 'pagination';
    const PATHLENGTH                      = 'pathlength';
    const PATTERN                         = 'pattern';
    const PATTERNCONTENTUNITS             = 'patterncontentunits';
    const PATTERNTRANSFORM                = 'patterntransform';
    const PATTERNUNITS                    = 'patternunits';
    const PAUSE                           = 'pause';
    const PAUSE_AFTER                     = 'pause-after';
    const PAUSE_BEFORE                    = 'pause-before';
    const PEEK                            = 'peek';
    const PERMISSION_DIALOG_URL           = 'permission-dialog-url';
    const PERSPECTIVE                     = 'perspective';
    const PERSPECTIVE_ORIGIN              = 'perspective-origin';
    const PITCH                           = 'pitch';
    const PITCH_END                       = 'pitch-end';
    const PITCH_RANGE                     = 'pitch-range';
    const PITCH_START                     = 'pitch-start';
    const PLACEHOLDER                     = 'placeholder';
    const PLACE_ITEMS                     = 'place-items';
    const PLAYSINLINE                     = 'playsinline';
    const POINTER_EVENTS                  = 'pointer-events';
    const POINTS                          = 'points';
    const POINTSATX                       = 'pointsatx';
    const POINTSATY                       = 'pointsaty';
    const POINTSATZ                       = 'pointsatz';
    const POOOL_ACCESS_CONTENT            = 'poool-access-content';
    const POOOL_ACCESS_PREVIEW            = 'poool-access-preview';
    const POSITION                        = 'position';
    const POSTER                          = 'poster';
    const POSTER_LANDSCAPE_SRC            = 'poster-landscape-src';
    const POSTER_PORTRAIT_SRC             = 'poster-portrait-src';
    const POSTER_SQUARE_SRC               = 'poster-square-src';
    const PREFETCH                        = 'prefetch';
    const PREFIX                          = 'prefix';
    const PRELOAD                         = 'preload';
    const PRESERVEALPHA                   = 'preservealpha';
    const PRESERVEASPECTRATIO             = 'preserveaspectratio';
    const PRESET                          = 'preset';
    const PRIMITIVEUNITS                  = 'primitiveunits';
    const PROFILE                         = 'profile';
    const PROMPT_SIZE                     = 'prompt-size';
    const PROMPT_TEXT                     = 'prompt-text';
    const PROPERTY                        = 'property';
    const PUBDATE                         = 'pubdate';
    const PUBLISHER                       = 'publisher';
    const PUBLISHER_CODE                  = 'publisher-code';
    const PUBLISHER_LOGO_SRC              = 'publisher-logo-src';
    const QUERY                           = 'query';
    const QUOTES                          = 'quotes';
    const R                               = 'r';
    const RADIUS                          = 'radius';
    const READONLY                        = 'readonly';
    const RECOMMENDATION_BOX              = 'recommendation-box';
    const REFERRERPOLICY                  = 'referrerpolicy';
    const REFX                            = 'refx';
    const REFY                            = 'refy';
    const REL                             = 'rel';
    const RENDERER                        = 'renderer';
    const REPORTINGORIGIN                 = 'reportingorigin';
    const REQUIRED                        = 'required';
    const REQUIREDEXTENSIONS              = 'requiredextensions';
    const REQUIREDFEATURES                = 'requiredfeatures';
    const RESET_ON_REFRESH                = 'reset-on-refresh';
    const RESET_ON_RESIZE                 = 'reset-on-resize';
    const RESIZABLE                       = 'resizable';
    const RESIZE                          = 'resize';
    const RESOURCE                        = 'resource';
    const RESULT                          = 'result';
    const REV                             = 'rev';
    const REVERSED                        = 'reversed';
    const RICHNESS                        = 'richness';
    const RIGHT                           = 'right';
    const ROLE                            = 'role';
    const ROTATE                          = 'rotate';
    const ROTATE_TO_FULLSCREEN            = 'rotate-to-fullscreen';
    const ROWS                            = 'rows';
    const ROWSPAN                         = 'rowspan';
    const ROW_GAP                         = 'row-gap';
    const RTC_CONFIG                      = 'rtc-config';
    const RX                              = 'rx';
    const RY                              = 'ry';
    const SANDBOX                         = 'sandbox';
    const SANDBOXED                       = 'sandboxed';
    const SCALE                           = 'scale';
    const SCALE_END                       = 'scale-end';
    const SCALE_START                     = 'scale-start';
    const SCENE_HEADING                   = 'scene-heading';
    const SCENE_PITCH                     = 'scene-pitch';
    const SCENE_ROLL                      = 'scene-roll';
    const SCHEME                          = 'scheme';
    const SCOPE                           = 'scope';
    const SCRIPT                          = 'script';
    const SCROLLABLE                      = 'scrollable';
    const SCROLLING                       = 'scrolling';
    const SECOND                          = 'second';
    const SEED                            = 'seed';
    const SELECTED                        = 'selected';
    const SELECTIONDIRECTION              = 'selectiondirection';
    const SELECTIONEND                    = 'selectionend';
    const SELECTIONSTART                  = 'selectionstart';
    const SEPARATOR                       = 'separator';
    const SERVICE_WORKER_SCOPE            = 'service-worker-scope';
    const SERVICE_WORKER_URL              = 'service-worker-url';
    const SHAPE_RENDERING                 = 'shape-rendering';
    const SHA_256_HASH                    = 'sha-256-hash';
    const SHOW_TOOLTIP                    = 'show-tooltip';
    const SIDE                            = 'side';
    const SINGLE_ITEM                     = 'single-item';
    const SIZE                            = 'size';
    const SIZES                           = 'sizes';
    const SKETCH_TYPE                     = 'sketch-type';
    const SLIDE                           = 'slide';
    const SLIDE_ALIGN                     = 'slide-align';
    const SLOPE                           = 'slope';
    const SLOT                            = 'slot';
    const SMOOTHING                       = 'smoothing';
    const SNAP                            = 'snap';
    const SNAP_ALIGN                      = 'snap-align';
    const SNAP_BY                         = 'snap-by';
    const SOLID_COLOR                     = 'solid-color';
    const SOLID_OPACITY                   = 'solid-opacity';
    const SORT                            = 'sort';
    const SORTABLE                        = 'sortable';
    const SORTED                          = 'sorted';
    const SPACING                         = 'spacing';
    const SPAN                            = 'span';
    const SPEAK                           = 'speak';
    const SPEAK_HEADER                    = 'speak-header';
    const SPEAK_NUMERAL                   = 'speak-numeral';
    const SPEAK_PUNCTUATION               = 'speak-punctuation';
    const SPECULARCONSTANT                = 'specularconstant';
    const SPECULAREXPONENT                = 'specularexponent';
    const SPEECH_RATE                     = 'speech-rate';
    const SPELLCHECK                      = 'spellcheck';
    const SPREADMETHOD                    = 'spreadmethod';
    const SRC                             = 'src';
    const SRCDOC                          = 'srcdoc';
    const SRCLANG                         = 'srclang';
    const SRCSET                          = 'srcset';
    const STANDALONE                      = 'standalone';
    const START                           = 'start';
    const STARTOFFSET                     = 'startoffset';
    const START_DATE                      = 'start-date';
    const START_INPUT_SELECTOR            = 'start-input-selector';
    const STDDEVIATION                    = 'stddeviation';
    const STEP                            = 'step';
    const STEP_SIZE                       = 'step-size';
    const STICKY                          = 'sticky';
    const STITCHTILES                     = 'stitchtiles';
    const STOP_COLOR                      = 'stop-color';
    const STOP_OPACITY                    = 'stop-opacity';
    const STRESS                          = 'stress';
    const STROKE                          = 'stroke';
    const STROKE_DASHARRAY                = 'stroke-dasharray';
    const STROKE_DASHOFFSET               = 'stroke-dashoffset';
    const STROKE_LINECAP                  = 'stroke-linecap';
    const STROKE_LINEJOIN                 = 'stroke-linejoin';
    const STROKE_MITERLIMIT               = 'stroke-miterlimit';
    const STROKE_OPACITY                  = 'stroke-opacity';
    const STROKE_WIDTH                    = 'stroke-width';
    const STYLE                           = 'style';
    const SUBMITTING                      = 'submitting';
    const SUBMIT_ERROR                    = 'submit-error';
    const SUBMIT_ON_ENTER                 = 'submit-on-enter';
    const SUBMIT_SUCCESS                  = 'submit-success';
    const SUBSCRIPTIONS_ACTION            = 'subscriptions-action';
    const SUBSCRIPTIONS_ACTIONS           = 'subscriptions-actions';
    const SUBSCRIPTIONS_DECORATE          = 'subscriptions-decorate';
    const SUBSCRIPTIONS_DIALOG            = 'subscriptions-dialog';
    const SUBSCRIPTIONS_DISPLAY           = 'subscriptions-display';
    const SUBSCRIPTIONS_GOOGLE_RTC        = 'subscriptions-google-rtc';
    const SUBSCRIPTIONS_LANG              = 'subscriptions-lang';
    const SUBSCRIPTIONS_SECTION           = 'subscriptions-section';
    const SUBSCRIPTIONS_SERVICE           = 'subscriptions-service';
    const SUGGEST_FIRST                   = 'suggest-first';
    const SUPPORTS_LANDSCAPE              = 'supports-landscape';
    const SURFACESCALE                    = 'surfacescale';
    const SWG_AMP_CACHE_NONCE             = 'swg-amp-cache-nonce';
    const SYSTEMLANGUAGE                  = 'systemlanguage';
    const TABINDEX                        = 'tabindex';
    const TABLE                           = 'table';
    const TABLEVALUES                     = 'tablevalues';
    const TABLE_LAYOUT                    = 'table-layout';
    const TAB_SIZE                        = 'tab-size';
    const TARGET                          = 'target';
    const TARGETX                         = 'targetx';
    const TARGETY                         = 'targety';
    const TEMPLATE                        = 'template';
    const TEXTLENGTH                      = 'textlength';
    const TEXT_ALIGN                      = 'text-align';
    const TEXT_ALIGN_LAST                 = 'text-align-last';
    const TEXT_ANCHOR                     = 'text-anchor';
    const TEXT_COMBINE_UPRIGHT            = 'text-combine-upright';
    const TEXT_DECORATION                 = 'text-decoration';
    const TEXT_DECORATION_COLOR           = 'text-decoration-color';
    const TEXT_DECORATION_LINE            = 'text-decoration-line';
    const TEXT_DECORATION_SKIP            = 'text-decoration-skip';
    const TEXT_DECORATION_SKIP_INK        = 'text-decoration-skip-ink';
    const TEXT_DECORATION_STYLE           = 'text-decoration-style';
    const TEXT_EMPHASIS                   = 'text-emphasis';
    const TEXT_EMPHASIS_COLOR             = 'text-emphasis-color';
    const TEXT_EMPHASIS_POSITION          = 'text-emphasis-position';
    const TEXT_EMPHASIS_STYLE             = 'text-emphasis-style';
    const TEXT_FILL_COLOR                 = 'text-fill-color';
    const TEXT_INDENT                     = 'text-indent';
    const TEXT_JUSTIFY                    = 'text-justify';
    const TEXT_ORIENTATION                = 'text-orientation';
    const TEXT_OVERFLOW                   = 'text-overflow';
    const TEXT_RENDERING                  = 'text-rendering';
    const TEXT_SHADOW                     = 'text-shadow';
    const TEXT_STROKE                     = 'text-stroke';
    const TEXT_STROKE_COLOR               = 'text-stroke-color';
    const TEXT_STROKE_WIDTH               = 'text-stroke-width';
    const TEXT_TRANSFORM                  = 'text-transform';
    const TEXT_UNDERLINE_POSITION         = 'text-underline-position';
    const THEME                           = 'theme';
    const TIMELEFT_MS                     = 'timeleft-ms';
    const TIMELINE_EVENT_PREFIX           = 'timeline-event-prefix';
    const TIMEOUT                         = 'timeout';
    const TIMESTAMP_MS                    = 'timestamp-ms';
    const TIMESTAMP_SECONDS               = 'timestamp-seconds';
    const TITLE                           = 'title';
    const TOOLBAR                         = 'toolbar';
    const TOOLBAR_TARGET                  = 'toolbar-target';
    const TOP                             = 'top';
    const TOUCH_KEYBOARD_EDITABLE         = 'touch-keyboard-editable';
    const TRACKING                        = 'tracking';
    const TRANSFORM                       = 'transform';
    const TRANSFORMED                     = 'transformed';
    const TRANSFORM_BOX                   = 'transform-box';
    const TRANSFORM_ORIGIN                = 'transform-origin';
    const TRANSFORM_STYLE                 = 'transform-style';
    const TRANSITION                      = 'transition';
    const TRANSITION_DELAY                = 'transition-delay';
    const TRANSITION_DURATION             = 'transition-duration';
    const TRANSITION_PROPERTY             = 'transition-property';
    const TRANSITION_TIMING_FUNCTION      = 'transition-timing-function';
    const TRANSLATE                       = 'translate';
    const TRANSLATE_X                     = 'translate-x';
    const TRANSLATE_Y                     = 'translate-y';
    const TRIGGER                         = 'trigger';
    const TYPE                            = 'type';
    const TYPEOF                          = 'typeof';
    const U1                              = 'u1';
    const U2                              = 'u2';
    const UNICODE                         = 'unicode';
    const UNICODE_BIDI                    = 'unicode-bidi';
    const UPDATE                          = 'update';
    const USEMAP                          = 'usemap';
    const USER_SELECT                     = 'user-select';
    const VALIDATION_FOR                  = 'validation-for';
    const VALIGN                          = 'valign';
    const VALUE                           = 'value';
    const VALUES                          = 'values';
    const VECTOR_EFFECT                   = 'vector-effect';
    const VERIFY_ERROR                    = 'verify-error';
    const VERIFY_XHR                      = 'verify-xhr';
    const VERSION                         = 'version';
    const VERTICAL_ALIGN                  = 'vertical-align';
    const VERT_ADV_Y                      = 'vert-adv-y';
    const VERT_ORIGIN_X                   = 'vert-origin-x';
    const VERT_ORIGIN_Y                   = 'vert-origin-y';
    const VIEWBOX                         = 'viewbox';
    const VIEWPORT                        = 'viewport';
    const VIEWPORT_MARGINS                = 'viewport-margins';
    const VIEWTARGET                      = 'viewtarget';
    const VISIBILITY                      = 'visibility';
    const VISIBLE_COUNT                   = 'visible-count';
    const VISIBLE_WHEN_INVALID            = 'visible-when-invalid';
    const VOCAB                           = 'vocab';
    const VOICE_FAMILY                    = 'voice-family';
    const VOLUME                          = 'volume';
    const VSPACE                          = 'vspace';
    const WEEK_DAY_FORMAT                 = 'week-day-format';
    const WHEN_ENDED                      = 'when-ended';
    const WHITE_SPACE                     = 'white-space';
    const WIDOWS                          = 'widows';
    const WIDTH                           = 'width';
    const WORD_BREAK                      = 'word-break';
    const WORD_SPACING                    = 'word-spacing';
    const WORD_WRAP                       = 'word-wrap';
    const WRAP                            = 'wrap';
    const WRITING_MODE                    = 'writing-mode';
    const X                               = 'x';
    const X1                              = 'x1';
    const X2                              = 'x2';
    const XCHANNELSELECTOR                = 'xchannelselector';
    const XLINK_ACTUATE                   = 'xlink-actuate';
    const XLINK_ARCROLE                   = 'xlink-arcrole';
    const XLINK_HREF                      = 'xlink-href';
    const XLINK_ROLE                      = 'xlink-role';
    const XLINK_SHOW                      = 'xlink-show';
    const XLINK_TITLE                     = 'xlink-title';
    const XLINK_TYPE                      = 'xlink-type';
    const XMLNS                           = 'xmlns';
    const XMLNS_XLINK                     = 'xmlns-xlink';
    const XML_LANG                        = 'xml-lang';
    const XML_SPACE                       = 'xml-space';
    const XSSI_PREFIX                     = 'xssi-prefix';
    const Y                               = 'y';
    const Y1                              = 'y1';
    const Y2                              = 'y2';
    const YCHANNELSELECTOR                = 'ychannelselector';
    const ZOOMANDPAN                      = 'zoomandpan';
    const ZOOM_END                        = 'zoom-end';
    const ZOOM_START                      = 'zoom-start';
    const Z_INDEX                         = 'z-index';
    const _MOZ_APPEARANCE                 = '-moz-appearance';
    const _WEBKIT_APPEARANCE              = '-webkit-appearance';
    const _WEBKIT_TAP_HIGHLIGHT_COLOR     = '-webkit-tap-highlight-color';
    const Z                               = 'z';

    const ALL_AMP       = [self::AMP, self::AMP_EMOJI, self::AMP_EMOJI_ALT];
    const ALL_AMP4ADS   = [self::AMP4ADS, self::AMP4ADS_EMOJI, self::AMP4ADS_EMOJI_ALT];
    const ALL_AMP4EMAIL = [self::AMP4EMAIL, self::AMP4EMAIL_EMOJI, self::AMP4EMAIL_EMOJI_ALT];

    const ALL_BOILERPLATES = [self::AMP_BOILERPLATE, self::AMP4ADS_BOILERPLATE, self::AMP4EMAIL_BOILERPLATE];

    const TYPE_HTML       = 'text/html';
    const TYPE_JSON       = 'application/json';
    const TYPE_LD_JSON    = 'application/ld+json';
    const TYPE_PDF        = 'application/pdf';
    const TYPE_MODULE     = 'module';
    const TYPE_TEXT_PLAIN = 'text/plain';

    const REL_AMPHTML       = 'amphtml';
    const REL_CANONICAL     = 'canonical';
    const REL_DNS_PREFETCH  = 'dns-prefetch';
    const REL_ICON          = 'icon';
    const REL_MODULEPRELOAD = 'modulepreload';
    const REL_NOAMPHTML     = 'noamphtml';
    const REL_NOFOLLOW      = 'nofollow';
    const REL_PRECONNECT    = 'preconnect';
    const REL_PREFETCH      = 'prefetch';
    const REL_PRELOAD       = 'preload';
    const REL_PRERENDER     = 'prerender';
    const REL_STYLESHEET    = 'stylesheet';

    const DATA_ACCOUNT                     = 'data-account';
    const DATA_ACTION                      = 'data-action';
    const DATA_AD_TAG_URL                  = 'data-ad-tag-url';
    const DATA_AMPDEVMODE                  = 'data-ampdevmode';
    const DATA_AMP_AUTOCOMPLETE_OPT_IN     = 'data-amp-autocomplete-opt-in';
    const DATA_AMP_BIND_SRC                = 'data-amp-bind-src';
    const DATA_AMP_STORY_PLAYER_POSTER_IMG = 'data-amp-story-player-poster-img';
    const DATA_APESTER_CHANNEL_TOKEN       = 'data-apester-channel-token';
    const DATA_APESTER_MEDIA_ID            = 'data-apester-media-id';
    const DATA_API_KEY                     = 'data-api-key';
    const DATA_APP_KEY                     = 'data-app-key';
    const DATA_BCID                        = 'data-bcid';
    const DATA_BORDER                      = 'data-border';
    const DATA_CALL_TO_ACTION_LABEL        = 'data-call-to-action-label';
    const DATA_CARDS                       = 'data-cards';
    const DATA_CAROUSEL                    = 'data-carousel';
    const DATA_CLIENT                      = 'data-client';
    const DATA_COLOR                       = 'data-color';
    const DATA_COMMENTS                    = 'data-comments';
    const DATA_CONTENT                     = 'data-content';
    const DATA_CONTENT_ID                  = 'data-content-id';
    const DATA_CONTENT_TYPE                = 'data-content-type';
    const DATA_CONVERSATION                = 'data-conversation';
    const DATA_COUNT_UP                    = 'data-count-up';
    const DATA_CSS_STRICT                  = 'data-css-strict';
    const DATA_DISMISS_HREF                = 'data-dismiss-href';
    const DATA_DO                          = 'data-do';
    const DATA_DOMAIN                      = 'data-domain';
    const DATA_DYNAMIC                     = 'data-dynamic';
    const DATA_EID                         = 'data-eid';
    const DATA_EMBEDCODE                   = 'data-embedcode';
    const DATA_EMBEDLIVE                   = 'data-embedlive';
    const DATA_EMBEDPARENT                 = 'data-embedparent';
    const DATA_EMBEDTYPE                   = 'data-embedtype';
    const DATA_EMBED_ID                    = 'data-embed-id';
    const DATA_ENABLE_REFRESH              = 'data-enable-refresh';
    const DATA_ENDSCREEN_ENABLE            = 'data-endscreen-enable';
    const DATA_EPISODE                     = 'data-episode';
    const DATA_EPISODES                    = 'data-episodes';
    const DATA_EXIT_MODE                   = 'data-exit-mode';
    const DATA_FORMULA                     = 'data-formula';
    const DATA_GFYID                       = 'data-gfyid';
    const DATA_GISTID                      = 'data-gistid';
    const DATA_HERO                        = 'data-hero';
    const DATA_HERO_CANDIDATE              = 'data-hero-candidate';
    const DATA_HREF                        = 'data-href';
    const DATA_ID                          = 'data-id';
    const DATA_IFRAME_SRC                  = 'data-iframe-src';
    const DATA_IMG                         = 'data-img';
    const DATA_IMGUR_ID                    = 'data-imgur-id';
    const DATA_INFO                        = 'data-info';
    const DATA_INTRO                       = 'data-intro';
    const DATA_ITEM                        = 'data-item';
    const DATA_ITEMS                       = 'data-items';
    const DATA_ITEM_INFO                   = 'data-item-info';
    const DATA_KEY                         = 'data-key';
    const DATA_LABEL                       = 'data-label';
    const DATA_LIGHT                       = 'data-light';
    const DATA_LIMIT                       = 'data-limit';
    const DATA_LIVE_CHANNELID              = 'data-live-channelid';
    const DATA_LOCALE                      = 'data-locale';
    const DATA_MAX_ITEMS_PER_PAGE          = 'data-max-items-per-page';
    const DATA_MEDIAID                     = 'data-mediaid';
    const DATA_MEDIA_HASHED_ID             = 'data-media-hashed-id';
    const DATA_MEDIA_ID                    = 'data-media-id';
    const DATA_MINIMUM_DATE_FACTOR         = 'data-minimum-date-factor';
    const DATA_MODE                        = 'data-mode';
    const DATA_MOMENTID                    = 'data-momentid';
    const DATA_MULTI_SIZE                  = 'data-multi-size';
    const DATA_MUTE                        = 'data-mute';
    const DATA_MY_CONTENT                  = 'data-my-content';
    const DATA_NAME                        = 'data-name';
    const DATA_ORIGIN                      = 'data-origin';
    const DATA_OUTRO                       = 'data-outro';
    const DATA_OUTSTREAM                   = 'data-outstream';
    const DATA_PARAM_VIDEOID               = 'data-param-videoid';
    const DATA_PARTNER                     = 'data-partner';
    const DATA_PCODE                       = 'data-pcode';
    const DATA_PID                         = 'data-pid';
    const DATA_PLAYER                      = 'data-player';
    const DATA_PLAYERID                    = 'data-playerid';
    const DATA_PLAYER_ID                   = 'data-player-id';
    const DATA_PLAYLIST                    = 'data-playlist';
    const DATA_PLAYLISTID                  = 'data-playlistid';
    const DATA_PLAYLIST_ID                 = 'data-playlist-id';
    const DATA_POLL_INTERVAL               = 'data-poll-interval';
    const DATA_PRODUCT_CODE                = 'data-product-code';
    const DATA_PROFILEID                   = 'data-profileid';
    const DATA_PUB_ID                      = 'data-pub-id';
    const DATA_RIDDLE_ID                   = 'data-riddle-id';
    const DATA_SCANNED_ELEMENT             = 'data-scanned-element';
    const DATA_SCANNED_ELEMENT_TYPE        = 'data-scanned-element-type';
    const DATA_SCOPED_KEYWORDS             = 'data-scoped-keywords';
    const DATA_SECRET_TOKEN                = 'data-secret-token';
    const DATA_SHARE_BUTTONS               = 'data-share-buttons';
    const DATA_SHARE_ENDPOINT              = 'data-share-endpoint';
    const DATA_SHARE_MEDIA                 = 'data-share-media';
    const DATA_SHARE_URL                   = 'data-share-url';
    const DATA_SHARING                     = 'data-sharing';
    const DATA_SHARING_ENABLE              = 'data-sharing-enable';
    const DATA_SHORTCODE                   = 'data-shortcode';
    const DATA_SHOW_IF_HREF                = 'data-show-if-href';
    const DATA_SITEKEY                     = 'data-sitekey';
    const DATA_SITE_ID                     = 'data-site-id';
    const DATA_SLOT                        = 'data-slot';
    const DATA_SORT_TIME                   = 'data-sort-time';
    const DATA_SPEAKABLE                   = 'data-speakable';
    const DATA_SRC                         = 'data-src';
    const DATA_START                       = 'data-start';
    const DATA_STORY_SUPPORTS_LANDSCAPE    = 'data-story-supports-landscape';
    const DATA_STREAMTYPE                  = 'data-streamtype';
    const DATA_TAG                         = 'data-tag';
    const DATA_TAGS                        = 'data-tags';
    const DATA_TERMS                       = 'data-terms';
    const DATA_TILE                        = 'data-tile';
    const DATA_TIMELINE_ID                 = 'data-timeline-id';
    const DATA_TIMELINE_OWNER_SCREEN_NAME  = 'data-timeline-owner-screen-name';
    const DATA_TIMELINE_SCREEN_NAME        = 'data-timeline-screen-name';
    const DATA_TIMELINE_SLUG               = 'data-timeline-slug';
    const DATA_TIMELINE_SOURCE_TYPE        = 'data-timeline-source-type';
    const DATA_TIMELINE_URL                = 'data-timeline-url';
    const DATA_TIMELINE_USER_ID            = 'data-timeline-user-id';
    const DATA_TOMBSTONE                   = 'data-tombstone';
    const DATA_TOOLTIP_ICON                = 'data-tooltip-icon';
    const DATA_TRACKID                     = 'data-trackid';
    const DATA_TRACKING_IDS                = 'data-tracking-ids';
    const DATA_TWEETID                     = 'data-tweetid';
    const DATA_UI_HIGHLIGHT                = 'data-ui-highlight';
    const DATA_UI_LOGO                     = 'data-ui-logo';
    const DATA_UPDATE_TIME                 = 'data-update-time';
    const DATA_URL                         = 'data-url';
    const DATA_VIDEO                       = 'data-video';
    const DATA_VIDEOID                     = 'data-videoid';
    const DATA_VINEID                      = 'data-vineid';
    const DATA_VISUAL                      = 'data-visual';
    const DATA_VOICE                       = 'data-voice';
    const DATA_WEBCARE_ID                  = 'data-webcare-id';
    const DATA_WIDGET_ID                   = 'data-widget-id';
    const DATA_WIDGET_TYPE                 = 'data-widget-type';
    const DATA_X                           = 'data-x';
    const DATA_Y                           = 'data-y';
    const DATA_ZOOM                        = 'data-zoom';

    const CROSSORIGIN_ANONYMOUS       = 'anonymous';
    const CROSSORIGIN_USE_CREDENTIALS = 'use-credentials';
}