title: What does the percent sign mean in Yaml?
body: <p>I noticed that in the i18n rails guide, they have the following code:</p>
  
  <pre><code>en:
    activerecord:
      errors:
        template:
          header:
            one:   "1 error prohibited this %{model} from being saved"
            other: "%{count} errors prohibited this %{model} from being saved"
          body:    "There were problems with the following fields:"
  </code></pre>
  
  <p>What do the <code>%{...}</code> mean? How is this different from <code>#{...}</code>?</p>