$element['uri']['#description']=t('Optional: provide a link to a map with the event location (e.g. https://uwaterloo.ca/map/). This must be an external URL such as https://example.com.');
// Set custom description for all link fields except event map.
$element['uri']['#description']=t('Start typing the title of a piece of content to select it. You can also enter an internal path such as /blog or an external URL such as https://example.com. Enter <front> to link to the front page.');
$element['uri']['#description']=t('Google Maps starts with https://www.google.com/maps/embed?pb=<br>Google My Maps starts with https://www.google.com/maps/d/u/1/embed?mid=');
}
// Set custom description only for event host field.