diff --git a/src/wp-admin/includes/export.php b/src/wp-admin/includes/export.php
index 25bf5e7fea..c645a894fd 100644
--- a/src/wp-admin/includes/export.php
+++ b/src/wp-admin/includes/export.php
@@ -18,12 +18,40 @@ define( 'WXR_VERSION', '1.2' );
 /**
  * Generates the WXR export file for download.
  *
+ * Default behavior is to export all content, however, note that post content will only
+ * be exported for post types with the `can_export` argument enabled. Any posts with the
+ * 'auto-draft' status will be skipped.
+ *
  * @since 2.1.0
  *
- * @global wpdb    $wpdb
- * @global WP_Post $post
+ * @global wpdb    $wpdb WordPress database abstraction object.
+ * @global WP_Post $post Global `$post`.
  *
- * @param array $args Filters defining what should be included in the export.
+ * @param array $args {
+ *     Optional. Arguments for generating the WXR export file for download. Default empty array.
+ *
+ *     @type string $content        Type of content to export. If set, only the post content of this post type
+ *                                  will be exported. Accepts 'all', 'post', 'page', 'attachment', or a defined
+ *                                  custom post If an invalid custom post type is supplied, every post type for
+ *                                  which `can_export` is enabled will be exported instead. If a valid custom post
+ *                                  type is supplied but `can_export` is disabled, then 'posts' will be exported
+ *                                  instead. When 'all' is supplied, only post types with `can_export` enabled will
+ *                                  be exported. Default 'all'.
+ *     @type string $author         Author to export content for. Only used when `$content` is 'post', 'page', or
+ *                                  'attachment'. Accepts false (all) or a specific author ID. Default false (all).
+ *     @type string $category       Category (slug) to export content for. Used only when `$content` is 'post'. If
+ *                                  set, only post content assigned to `$category will be exported. Accepts false
+ *                                  or a specific category slug. Default is false (all categories).
+ *     @type string $start_date     Start date to export content from. Expected date format is 'Y-m-d'. Used only
+ *                                  when `$content` is 'post', 'page' or 'attachment'. Default false (since the
+ *                                  beginning of time).
+ *     @type string $end_date       End date to export content to. Expected date format is 'Y-m-d'. Used only when
+ *                                  `$content` is 'post', 'page' or 'attachment'. Default false (latest publish date).
+ *     @type string $status         Post status to export posts for. Used only when `$content` is 'post' or 'page'.
+ *                                  Accepts false (all statuses except 'auto-draft'), or a specific status, i.e.
+ *                                  'publish', 'pending', 'draft', 'auto-draft', 'future', 'private', 'inherit', or
+ *                                  'trash'. Default false (all statuses except 'auto-draft').
+ * }
  */
 function export_wp( $args = array() ) {
 	global $wpdb, $post;