updated sitelinks, the column of sub-links beneath a Google search result that allows navigation straight to pages within a main site. The update makes sitelinks more visible, gives them flexible rankings based on the particular search query, increases the maximum number from eight to 12, and establishes a clearer hierarchy for the domains of search results.Google has
Under the hood, the update also improves the quality of sitelink results. The signals Google uses specifically to generate and rank sitelinks, such as the link structure of a site, are now combined with the overall ranking algorithm, so main search results and sitelinks are now ranked and displayed based on one unified set of principles.
Sitelinks can be managed by site administrators from Google's Webmaster Tools. Now that sitelinks have flexible rankings, Webmaster Tools allows administrators to suggest demotions, with a maximum of 100 demotions per site, instead of setting a fixed list of sitelinks. The option for one-line sitelinks has not changed, and Google says that "existing best practices for the link structure of your site are still relevant today," despite the updated ranking system.