<link rel="help" href="https://www.w3.org/TR/filter-effects-1/#funcdef-filter-brightness">
    <link rel="help" href="https://www.w3.org/TR/filter-effects-1/#funcdef-filter-sepia">
    <link rel="help" href="https://www.w3.org/TR/filter-effects-1/#funcdef-filter-grayscale">
    <link rel="help" href="https://www.w3.org/TR/filter-effects-1/#funcdef-filter-saturate">
    <link rel="help" href="https://www.w3.org/TR/filter-effects-1/#funcdef-filter-hue-rotate">
    <link rel="help" href="https://www.w3.org/TR/