;--shiki-dark:#E1E4E8;">)</span></span></code></pre></div><p>The <code>input_name</code> is the same value you used when creating your form class, and <code>key</code> is an <a href="/i18n.html">I18n</a> key that will have <code>cv.ss</code> prepended to it (for **c*onstratin <strong>v</strong>iolation, <strong>s</strong>server <strong>s</strong>ide). Thus, the key in the above example is <code>&quot;cv.ss.name_is_taken&quot;</code>.</p><p>Brut forms will automatically add client-side constraints based on t