wp-includes/widgets/class-wp-widget-custom-html.php:302Add help text to widgets admin screen.
public static function add_help_text() { $screen = get_current_screen(); $content = '<p>'; $content .= __( 'Use the Custom HTML widget to add arbitrary HTML code to your widget areas.' ); $content .= '</p>'; if ( 'false' !== wp_get_current_user()->syntax_highlighting ) { $content .= '<p>'; $content .= sprintf( /* translators: 1: Link to user profile, 2: Additional link attributes, 3: Accessibility text. */ __( 'The edit field automatically highlights code syntax. You can disable this in your <a href="%1$s" %2$s>user profile%3$s</a> to work in plain text mode.' ), esc_url( get_edit_profile_url() ), 'class="external-link" target="_blank"', sprintf( '<span class="screen-reader-text"> %s</span>', /* translators: Hidden accessibility text. */ __( '(opens in a new tab)' ) ) ); $content .= '</p>'; $content .= '<p id="editor-keyboard-trap-help-1">' . __( 'When using a keyboard to navigate:' ) . '</p>'; $content .= '<ul>'; $content .= '<li id="editor-keyboard-trap-help-2">' . __( 'In the editing area, the Tab key enters a tab character.' ) . '</li>'; $content .= '<li id="editor-keyboard-trap-help-3">' . __( 'To move away from this area, press the Esc key followed by the Tab key.' ) . '</li>'; $content .= '<li id="editor-keyboard-trap-help-4">' . __( 'Screen reader users: when in forms mode, you may need to press the Esc key twice.' ) . '</li>'; $content .= '</ul>'; } $screen->add_help_tab( array( 'id' => 'custom_html_widget', 'title' => __( 'Custom HTML Widget' ), 'content' => $content, ) ); }Introduced in 4.9.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/widgets/class-wp-widget-custom-html.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.