htmlid is a generated value that is a guaranteed safe and
unique string that can be used as an HTML element ID for an element within the current
component, template, or page. For example, it could be used as the ID for a DIV element
surrounding the component markup, passed in to client-side JavaScript to allow easy dynamic
manipulation of the component markup by using Ajax updates or similar.
For
example:
<div id="${htmlid}">your component markup here</div>