Use the cx:continue element to stop the evaluation of the current item in a cx:foreach loop and continue with the next item in the list.
Usually the cx:continue element is applied in combination with the cx:if element, like in:
<cx:if condition="item.name = 'Unknown'">
<cx:continue/>
</cx:if>
Usually the cx:continue element does not have any content and thus the short notation can be used (the / at the end of the opening tag).
See also the general description of the element.