Taxonomy: Add an explanation for "Parent" dropdown for hierarchical custom taxonomies.

Props F J Kaiser, raggedrobins, DrewAPicture, diddledan, SergeyBiryukov.
Fixes #23447.
Built from https://develop.svn.wordpress.org/trunk@39895


git-svn-id: http://core.svn.wordpress.org/trunk@39832 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/edit-tag-form.php

@@ -166,6 +166,8 @@ do_action( "{$taxonomy}_term_edit_form_top", $tag, $taxonomy );
 				wp_dropdown_categories( $dropdown_args ); ?>
 				<?php if ( 'category' == $taxonomy ) : ?>
 					<p class="description"><?php _e( 'Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.' ); ?></p>
+				<?php else : ?>
+					<p class="description"><?php _e( 'Assign a parent term to create a hierarchy. The term Jazz, for example, would be the parent of Bebop and Big Band.' ); ?></p>
 				<?php endif; ?>
 			</td>
 		</tr>

wp-admin/edit-tags.php

@@ -436,8 +436,10 @@ do_action( "{$taxonomy}_term_new_form_tag" );
 
 	wp_dropdown_categories( $dropdown_args );
 	?>
-	<?php if ( 'category' == $taxonomy ) : // @todo: Generic text for hierarchical taxonomies ?>
+	<?php if ( 'category' == $taxonomy ) : ?>
 		<p><?php _e( 'Categories, unlike tags, can have a hierarchy. You might have a Jazz category, and under that have children categories for Bebop and Big Band. Totally optional.' ); ?></p>
+	<?php else : ?>
+		<p><?php _e( 'Assign a parent term to create a hierarchy. The term Jazz, for example, would be the parent of Bebop and Big Band.' ); ?></p>
 	<?php endif; ?>
 </div>
 <?php endif; // is_taxonomy_hierarchical() ?>

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-39894';
+$wp_version = '4.8-alpha-39895';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.