Don’t Want All Pages in Nav-Bar: How Suppress?

My theme has a simple navigation bar at the top…and when I create a new page, it appears up there.

There are some pages I want to create that I want to publish but do not want listed in my nav-bar…. like certain administrative pages etc.

So…I want to selectively delete the listing in the nav-bar…but not the page itself.

My theme does not have an editor to suppress this….is there away to do this in the WP editor in the code?

Thanks,

Kirk