title: What are -webkit-paged-y and -webkit-paged-x values for overflow
body: <p>I've looked around SO but the questions I've found having anything to do with <code>overflow: -webkit-paged-y</code> or <code>overflow: -webkit-paged-x</code> don't explain what they are or do. Presumably, these prefixes would just be additions for <code>paged-x</code> or <code>y</code> but there is no <code>overflow</code> property value named so. On Chrome and Safari, those values seem to add a height (auto) for the entire container making everything fit without any fuss. </p>
  
  <p>I used these on a deeply nested markup and it worked, but I have no clue what those values are or why they worked. Information on them is scarce as well.  </p>