title: Indenting a YAML sequence inside a mapping
body: <p>Should the following be valid?</p>
  
  <pre><code>parent:
  - child
  - child
  </code></pre>
  
  <p>So what we have is a sequence of values inside a mapping.</p>
  
  <p>The specific question is about whether the indentation for the 2nd and 3rd lines is valid.  The Ruby YAML.dump generated this code, but the Yaml parser <a href="http://www.codeproject.com/KB/recipes/yamlparser.aspx" rel="noreferrer">here</a> rejects it, because the child lines are not indented.</p>
  
  <p>i.e. it wants something like:</p>
  
  <pre><code>parent:
    - child
    - child
  </code></pre>
  
  <p>Who is right?</p>
  
  <p>Looking at the YAML spec, it's certainly not obvious, and the line</p>
  
  <blockquote>
    <p>The “-”, “?” and “:” characters used to denote block collection entries are perceived by people to be part of the indentation</p>
  </blockquote>
  
  <p>doesn't help much.</p>