Sometimes the use of invisible characters is needed in order to trick certain mobile devices into not detecting dates within text.
Within your account however, there is the possibility that using these invisible characters at the beginning of a hyperlink inside an <a> tag, could cause the clicks on that link to not be included in your reports.
This is obviously undesirable, so one must be careful to not use the invisible character in such a location in your HTML.
This is the markup for the invisible character :
Here is an example of what not to do :
<a href="​http://www.linkURL.com">Click here to win!</a>