You can use a plugin such as
WordPress SEO by Yoast (which is a popular
SEO plugin amongst members of our community using ClassiPress), and one of the
features of this is:
When Google introduced the canonical link element, to distinguish the “original” page from derivative pages within your site carrying the same content, they reached out to me to develop a WordPress plugin for it, and I did. Later on, canonical link elements were added to core. They work fine, with one caveat: they only work for single posts and pages, not for categories and tags, not for the homepage. The WordPress SEO plugin fixes that, and sets the correct canonical on each of those pages.
In terms of the URL you can see the default structure on the
ClassiPress demo site. Our themes use custom post types, so the ad category is displayed in the URL. On that link you can also see the advanced search functionality which is determined by the custom fields you choose to have in the sidebar. If you are looking for specific sort functionality for ClassiPress search results, you may also like to look at some of the available plugins in the
AppThemes marketplace which are specifically for that purpose. Thanks.
