The mu-plugins folder in a WordPress install works only in WordPress MU (or Multisite)

If a file named 'plugin-install.php' is in your plugin folder:

What is the function used to create dashboard widgets?

How do you get the ID of the current post outside the loop?

Which WordPress functions doesn't exist?

What is the default post_status for attachments?

What Filter Hook is used to modify the output of the_content()?

What functions are used to safely add a style file to wordpress generated page?

How to add multiple headers in your theme ?

This function allows quick publishing with a web browser bookmarklet. You can create a post by quoting some text, images, and videos on any web page.

Which is NOT a core post type?