Index: gio/gfileinfo.h
===================================================================
--- gio/gfileinfo.h	(revision 7617)
+++ gio/gfileinfo.h	(working copy)
@@ -608,6 +608,21 @@
  **/
 #define G_FILE_ATTRIBUTE_THUMBNAILING_FAILED "thumbnail::failed"         /* boolean */
 
+/* Preview */
+
+/**
+ * G_FILE_ATTRIBUTE_PREVIEW_ICON:
+ *
+ * A key in the "preview" namespace for getting a #GIcon that can be
+ * used to get preview of the file. For example, it may be a low
+ * resolution thumbnail without metadata. Corresponding
+ * #GFileAttributeType is %G_FILE_ATTRIBUTE_TYPE_OBJECT.  The value
+ * for this key should contain a #GIcon.
+ *
+ * Since: 2.20
+ **/
+#define G_FILE_ATTRIBUTE_PREVIEW_ICON "preview::icon"         /* object (GIcon) */
+
 /* File system info (for g_file_get_filesystem_info) */
 
 /**
