Code to “noindex” Multiple Tag Archives in WordPress

/* No Index Multiple Categories */
add_action('wp_head', 'wpflt_header_function_condition_noindex_multiple_tags');
function wpflt_header_function_condition_noindex_multiple_tags(){
if ( is_tag( array( '312', '313' ) ) ) { ?>
<meta name="robots" content="noindex" />
<?php }
};

This code will add ‘noindex’ metatag to the header of specific Tag pages in WordPress and these Tag pages will not be indexed. Add the Tag IDs in line 4.