surement being
‘<code>HEIGHTCM</code>’, ‘<code>LENGTHCM</code>’, or
‘<code>WEIGHTKG</code>’</li>
<li>
<code>agedays</code> - a numeric value for age in days at time of
measurement; will be rounded down (floor) to nearest integer if needed
(note that there are 30.4375 days in one month; see also the additional
<a href="https://www.cdc.gov/nccdphp/dnpao/growthcharts/resources/sas.htm" class="external-link">notes
on calculating <code>agemos</code></a> from whole numbers of months</li>
<li>
<code>se