WPSEO_Upgrade::upgrade_70() – Perform the 7.0 upgrade, moves settings around, deletes several options.
WPSEO_Upgrade::upgrade_61() – Updates the links for the link count when there is a difference between the site and home url. We’ve used the site url instead of the 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_50_51() – Updates the internal_link_count column to support improved functionality.
WPSEO_Upgrade::upgrade_49() – Removes the ‘wpseo-dismiss-about’ notice for every user that still has it.
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_21() – Detects if taxonomy terms were split and updates the corresponding taxonomy meta’s accordingly.
SimplePie_Misc::windows_1252_to_utf8() – Converts a Windows-1252 encoded string to a UTF-8 encoded string
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