After reading through the Wordpress documentation, I recognized you are able to remove posts in the index using filters inside "The Loop", e.g.:

<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>

<!-- The following tests if the current post is in category 3. -->
<?php if (in_category('3')) continue; ?>

<!-- display normal post -->
<?php endwhile; else: ?>
<p>Sorry, no posts matched your criteria.</p>
<?php endif; ?>

What I am wondering is that if there's a filter/hook to filter posts in have_posts() without modifying web site. To date, I discovered choices to alter the results, although not remove results make up the result set.

Would you like to take it out of exhibiting but nonetheless get it 'there' incase you choose to show it later? Not necessarily obvious on which for you to do.

As you example, previously I have used Query Posts keep groups from my home page: