Handle_404::is_feed_404() – If there are no posts in a feed, make it 404 instead of sending an empty RSS feed.
Indexable_Head_Action::for_404() – Retrieves the head for the 404 page. Always sets the status to 404.
WPSEO_Handle_404::is_feed_404() – If there are no posts in a feed, make it 404 instead of sending an empty RSS feed.
WPSEO_Upgrade::upgrade_21() – Detects if taxonomy terms were split and updates the corresponding taxonomy meta’s accordingly.
WPSEO_Upgrade::upgrade_44() – Moves the content-analysis-active and keyword-analysis-acive options from wpseo-titles to wpseo.
WPSEO_Upgrade::upgrade_47() – Renames the meta name for the cornerstone content. It was a public meta field and it has to be private.
WPSEO_Upgrade::upgrade_49() – Removes the ‘wpseo-dismiss-about’ notice for every user that still has it.
WPSEO_Upgrade::upgrade_50_51() – Updates the internal_link_count column to support improved functionality.
WPSEO_Upgrade::upgrade_61() – Updates the links for the link count when there is a difference between the site and home url.
WPSEO_Upgrade::upgrade_63() – Removes some no longer used options for noindexing subpages and for meta keywords and its associated templates.
WPSEO_Upgrade::upgrade_70() – Perform the 7.0 upgrade, moves settings around, deletes several options.
