So I have the following:

piklist('field', array(
  'type'      => 'text',
  'field'     => 'video',
  'label'     => 'Video',
  'validate'  => array(
    array(
      'type'    => 'youtube-urls'
    ),
    array(
      'type'    => 'vimeo-share-url'
    )
  )
));

After I did that, it occurred to me that I’m not sure if the validations use either an AND or OR. That is, I want the text to either be a youtube or vimeo url. I looked at the doc and didn’t see anything that specifies this or gives the ability to change the comparison operator.