title: YAML, Docker Compose, Spaces & Quotes
body: <p>Under what circumstances <strong>must</strong> one use quotes in a YAML file, specifically when using <code>docker-compose</code>.</p>
  
  <p>For instance,</p>
  
  <pre><code>service:
    image: "my-registry/repo:tag1"
    environment:
      ENV1: abc
      ENV2: "abc"
      ENV3: "a b c"
  </code></pre>
  
  <p>If spaces are required, for example, must one use quotes around the environment variable, as depicted in <code>ENV3</code>?</p>