Some users would like to exclude certain tags from the posts page. This can be done with the following PHP snippet:
function exclude_posts( $query ) {
if ( $query->is_home() ) {
$query->set( 'tag__not_in', array( 13 , 26 ) );
}
}
add_action( 'pre_get_posts', 'exclude_posts' );
Simply edit your tag IDs in there instead of the 13 and 26 (examples).