I just ran into a problem when I was attempting to pass a PHP POST variable that contained a period. I’m not sure why I have never run into this situation in the past. PHP will automatically convert a period into an underscore. I submitted a form with a field with the name ‘co.uk’. I then checked for the existence of the post variable in a PHP class (if $_POST[‘co.uk’]). It did not exist. I then checked (if $_POST[‘co_uk’]) and was able to get the value. Interesting.