title: How to use multiple prefixes in anything-but clause in AWS eventbridge eventpattern?
body: <p>I have a situation where I need to filter out certain events using eventpatterns in eventbridge.
  I want to run the rule for all events except those where username starts with abc or xyz.
  I have tried below 2 syntax but none worked :</p>
  <pre><code>&quot;userIdentity&quot;: {
        &quot;sessionContext&quot;: {
          &quot;sessionIssuer&quot;: {
            &quot;userName&quot;: [
              {
                &quot;anything-but&quot;: {
                  &quot;prefix&quot;: [
                    &quot;abc-&quot;,
                    &quot;xyz-&quot;
                  ]
                }
              }
            ]
          }
        }
      }
  
  &quot;userIdentity&quot;: {
        &quot;sessionContext&quot;: {
          &quot;sessionIssuer&quot;: {
            &quot;userName&quot;: [
              {
                &quot;anything-but&quot;: [{
                  &quot;prefix&quot;: &quot;abc-&quot;,
                  &quot;prefix&quot;: &quot;xyz-&quot;
                }]
              }
            ]
          }
        }
      }
  </code></pre>
  <p>Getting following error on saving the rule :
  &quot;<em>Event pattern is not valid. Reason: Inside anything but list, start|null|boolean is not supported.</em>&quot;</p>
  <p>Am I missing something in the syntax or if this is a limitation then is there any alternative to this problem?</p>