Category page NOINDEX,NOFOLLOW when filters applied. Most websites are getting duplicated content issues at SEO when filters applied To avoid the issue we need to mark the category page’s meta robots value to `NOINDEX,NOFOLLOW` when the filter is applied on the category page. Defined an observer on event layout_generate_blocks_after The Observer class code will be Module is available at https://github.com/devamitbera/Magento2-extension/tree/master/Category-disallow/