Extension:SocialProfile/Hooks/UserProfileRightSideAfterActivity
For more information about attaching hooks, see Manual:Hooks.
For examples of other extensions using this hook, see Category:UserProfileRightSideAfterActivity extensions.
The UserProfileRightSideAfterActivity hook is called in the UserProfilePage class, when building the right-side (for left-to-right languages) items, before the listing of casual games (if enabled in site configuration/if the relevant extensions—PictureGame, PollNY, QuizGame—are installed on the wiki) but after the listing of the user's recent on-wiki activity (again, if enabled in site configuration).
It is somewhat of a purpose-built hook, added in July 2011, that basically exists (only) for the BlogPage extension, to avoid having to hard-code information about BlogPage into the UserProfilePage class, as not all wikis may wish to install BlogPage even if they choose to install SocialProfile.