
<dd><p>Unlike continuous scales, discrete scales can easily show
missing values, and do so by default. If you want to remove missing values
from a discrete scale, specify <code>na.translate = FALSE</code>.</p></dd>

    <dt><code>na.value</code></dt>
<dd><p>If <code>na.translate = TRUE</code>, what aesthetic value should the
missing values be displayed as? Does not apply to position scales
where <code>NA</code> is always placed at the far right.</p></dd>

    <dt><code>drop</code></dt>
<dd><p>Sh