Sometimes you may want to have a tab in the navigation which is non-clickable because you have other links or pages in the tab drop-down which you want visitors to click on instead.
E.g.
Home | About | Events <- non clickable, so on hover the dropdown tabs appear and people can click on those instead
Fundraisers <- clickable
Local Events <- clickable
Book Tickets <- clickable
In this scenario, you would edit the "Events" page and scroll down to the section where it says:
If you want you can set this page to be an external link rather than a normal page, just type the link location in the box below, leave the box blank to keep as a normal page
Enter this as the URL:
javascript:void(0)
and then save the page.