 as well.

  Returns the decorated string.
  ``</span>
  [<span class="mdzsyn-symbol">some-str</span> <span class="mdzsyn-symbol">&amp;opt</span> <span class="mdzsyn-symbol">flags</span>]
  (<span class="mdzsyn-coresym">var</span> <span class="mdzsyn-symbol">u-flag-set</span> <span class="mdzsyn-constant">false</span>)
  (<span class="mdzsyn-coresym">var</span> <span class="mdzsyn-symbol">b-flag-set</span> <span class="mdzsyn-constant">false</span>)
  (<span class="mdzsyn-coresym">when</span> <span class="m