What is the meta-box-order_post_hash used for?

by

I could only find the following core code references for the meta-box-order_ string:

/wp-admin/includes/ajax-actions.php: 
   update_user_option($user->ID, "meta-box-order_$page", $order, true);

and 

/wp-admin/includes/template.php: 
    ... get_user_option( "meta-box-order_$page" ) ...

that’s related to the ordering of meta-boxes.

I doubt your $page value is post_hash, so my first guess is that this comes from a plugin/theme? If not then the user option might be dynamically constructed.

Searching the wide world web gave be only this plugin on GitHub, that uses the meta-box-order_post_hash user meta key.

Thanks to @toscho for the information about the handy y key on GitHub, to retrieve permanent links to GitHub files that I didn’t use in previous answers 😉