diff --git src/wp-includes/class-wp-taxonomy.php src/wp-includes/class-wp-taxonomy.php
index 94353d8..1836f2a 100644
--- src/wp-includes/class-wp-taxonomy.php
+++ src/wp-includes/class-wp-taxonomy.php
@@ -152,6 +152,13 @@ final class WP_Taxonomy {
 	public $cap;
 
 	/**
+	 * Whether this taxonomy should remember the order in which terms are added to objects
+	 *
+	 * @var bool
+	 */
+	public $sort;
+
+	/**
 	 * Rewrites information for this taxonomy.
 	 *
 	 * @since 4.7.0
@@ -267,6 +274,7 @@ final class WP_Taxonomy {
 			'meta_box_cb'           => null,
 			'meta_box_sanitize_cb'  => null,
 			'capabilities'          => array(),
+			'sort'                  => false,
 			'rewrite'               => true,
 			'query_var'             => $this->name,
 			'update_count_callback' => '',
diff --git src/wp-includes/taxonomy.php src/wp-includes/taxonomy.php
index df828b0..97589c1 100644
--- src/wp-includes/taxonomy.php
+++ src/wp-includes/taxonomy.php
@@ -377,6 +377,8 @@ function is_taxonomy_hierarchical( $taxonomy ) {
  *         @type string $delete_terms Default 'manage_categories'.
  *         @type string $assign_terms Default 'edit_posts'.
  *     }
+ *     @type bool          $sort                  Whether this taxonomy should remember the order in which terms are
+ *                                                added to objects. Default false.
  *     @type bool|array    $rewrite {
  *         Triggers the handling of rewrites for this taxonomy. Default true, using $taxonomy as slug. To prevent
  *         rewrite, set to false. To specify rewrite rules, an array can be passed with any of these keys: