ss="sourceCode R"><span><span class="co"># Remove undecided/unspecified</span></span>
<span><span class="va">DT</span> <span class="op">&lt;-</span> <span class="va">DT</span><span class="op">[</span><span class="op">!</span><span class="va">cip6</span> <span class="op"><a href="https://rdrr.io/pkg/data.table/man/like.html" class="external-link">%like%</a></span> <span class="st">"999999"</span><span class="op">]</span></span>
<span><span class="va">DT</span></span>
<span><span class="co">#&gt;             