'Show / Enable' tool turned off you
can only see one of them:
The 'Show / Enable' tool will make all of the hidden fields visible and allow you to change them.
As the fields are normally hidden the 'Show / Enable' tool shows a count of the number of hidden fields.
So if you see that this count is ever greater than zero then you will know that the page has that number
of hidden fields in it.
Fields revealed by this tool will be outlined in purple so that you can easily identify them.