Registers support of certain features for a post type.

Registers a settings error to be displayed to the user.

Adds meta data to a user.

Displays relational links for the posts adjacent to the current post for single post pages.

Displays the default admin color scheme picker (Used in user-edit.php).

Allow subdirectory installation.

Allow subdomain installation

Calls the callback functions that have been added to a filter hook, specifying arguments in an array.

Enable/disable automatic general feed link outputting.

Avoids a collision between a site slug and a permalink slug.