config.yml

# Site settings
title: Your awesome title
email: your-email@domain.com
description: "Write an awesome description for your new site here. You can edit this line in _config.yml. It will appear in your document head meta (for Google search results) and in your feed.xml site description."
baseurl: ""
url: "http://yourdomain.com"

# Build settings
markdown: kramdown

defaults:
  -
    scope:
      path: ""
    values:
      layout: default
  -
    scope:
      path: "_posts"
    values:
      layout: "post"
      permalink: "/posters/:title"

The _posts scope layout value is picked up, but not the permalink.

Bummer. All the docs led me to believe it should be.

It seems that no matter what I do, when Jekyll builds, it always creates directories/subdirectories based on the date. :/