If you update your site to WordPress 4.9.8, you’ll find a “Try Gutenberg” callout on the dashboard. Who sees this and can it be switched off?

Who sees the callout?

• If Gutenberg is not installed or activated, the callout will be shown to Admin users on single sites, and Super Admin users on multisites (based on the install_plugins capability).
• If Gutenberg is installed and activated, the callout will be shown to Contributor users and above (based on the edit_posts capability).
• If the Classic Editor plugin is installed and activated, the callout will be hidden for all users.

How to switch off the callout

If you wish to turn it off, simply add the following code to your theme’s functions.phpfile…

remove_action( 'try_gutenberg_panel', 'wp_try_gutenberg_panel' );

How to customise the callout link

The callout directs readers to https://wordpress.org/gutenberg to learn more about Gutenberg. But if you have your own documentation on the subject that you’re prefer your site users to read, then this link can be modified…

function my_host_learn_more_link( $link ) {
    return '<a href="https://support.my.host/gutenberg">Learn more about Gutenberg at My Host</a>';
}
 
add_filter( 'try_gutenberg_learn_more_link', 'my_host_learn_more_link' );

This allows you to change both the link text and the URL.