title: What does 'LHS' mean in a message from the ESLint plugin for Vue.js?
body: <p><a href="https://github.com/vuejs/eslint-plugin-vue/blob/master/docs/rules/valid-v-model.md#book-rule-details" rel="noreferrer">A message from the official ESLint plugin for Vue.js</a> says:</p>
  
  <blockquote>
    <p>'v-model' directives require the attribute value which is valid as
    LHS.</p>
  </blockquote>
  
  <p>An example which triggers that message is</p>
  
  <pre><code>&lt;input v-model="foo() + bar()"&gt;
  </code></pre>
  
  <p>What does LHS mean?</p>