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Set appropriate post information for your site.

In 5.x:
In (Administer > Site building > themes), select the "configure" tab, then "Global settings." Select the appropriate "Display post information on" that are right for your site.

Available options will be determined by the installed modules on your site. Other options can be configured on the individual theme's configuration page.

In 4.7 and before:
In (administer > themes) (URL: ?q=admin/themes/settings) menu, select the "configure tab" and "Global settings" sub-tab. Select the appropriate options for your site in the "Display post information" menu.