What Meat Puppet suggested was a comment. They are only visible in the source of the page and the format is:
Code:
<!-- text here doesn't appear on the page -->
If you wanted to put some text on your page, but still have it invisible, you could use something like this:
Code:
<span style="color: transparent; background: transparent;"> Text here is transparent. <span>
But Meat Puppet's suggestion is obviously better.