In february 2009, the major search engines introduced the
rel="canonical"element. This is another utility to help fight duplicate content. WordPress has built-in support for canonical link elements on single posts and pages, but it has some slight bugs in that. It doesn’t output canonical links on any other page. With our WordPress SEO plugin activated, you automatically get canonical link elements for every page type in WordPress.
Realisation on snbchf.com
Our structure is very good and we don’t have duplicated content. Our slugs are good, too. There is no any chance to make duplicate content or page. So we don’t need neither cannical tag, nor noindex.