On: WebP is so great except it's not (2021)

[angiosperm]

I see:

  {
    font-family: 'Linux Libertine';
    font-variant-numeric: oldstyle-nums;
    font-variant-ligatures: common-ligatures discretionary-ligatures contextual historical-ligatures;
    text-rendering: geometricprecision;
    font-kerning: normal;
  }

I guess those are "historical ligatures". I personally persuaded the creator of the Linux Libertine face used in the page to add those to it.