I created a template that has Facebook, Twitter and LinkedIn share butotns (which share an event page). It works correctly however when I test it, however, when I do the HTML validation I get the following errors:

line 582 column 171 - Warning: unescaped & or unknown entity "&url"
line 585 column 62 - Warning: unescaped & or unknown entity "&url"
line 582 column 7 - Warning: <a>...