+notmuch_message_maildir_flags_to_tags (notmuch_message_t *message);
+
+/* Rename message filename(s) to encode tags as maildir flags
+ *
+ * Specifically, for each filename corresponding to this message:
+ *
+ * If the filename is not in a maildir directory, do nothing.
+ * (A maildir directory is determined as a directory named "new" or
+ * "cur" with a neighboring directory named respectively "cur" or
+ * "new".)
+ *
+ * If the filename is in a maildir directory, rename the file so that
+ * its filename ends with the sequence ":2," followed by zero or more
+ * of the following single-character flags (in ASCII order):
+ *
+ * 'D' if the message has the "draft" tag
+ * 'F' if the message has the "flagged" tag
+ * 'P' if the message has the "passed" tag
+ * 'R' if the message has the "replied" tag
+ * 'S' if the message does not have the "unread" tag
+ *
+ * Any existing flags unmentioned in the list above are left
+ * unaffected by the rename.
+ *
+ * Also, if this filename is in a directory named "new", rename it to
+ * be within the neighboring directory named "cur".
+ *
+ * A client can ensure that maildir filename flags remain synchronized
+ * with notmuch database tags by calling this function after changing
+ * tags, (after calls to notmuch_message_add_tag,
+ * notmuch_message_remove_tag, or notmuch_message_freeze/
+ * notmuch_message_thaw). See also notmuch_message_maildir_flags_to_tags
+ * for synchronizing maildir flag changes back to tags.
+ */
+notmuch_status_t
+notmuch_message_tags_to_maildir_flags (notmuch_message_t *message);