- * The following functions add a reference check or update to a
- * ref_transaction. In all of them, refname is the name of the
- * reference to be affected. The functions make internal copies of
- * refname and msg, so the caller retains ownership of these parameters.
- * flags can be REF_NODEREF; it is passed to update_ref_lock().
+ * Reference transaction updates
+ *
+ * The following four functions add a reference check or update to a
+ * ref_transaction. They have some common similar parameters:
+ *
+ * transaction -- a pointer to an open ref_transaction, obtained
+ * from ref_transaction_begin().
+ *
+ * refname -- the name of the reference to be affected.
+ *
+ * flags -- flags affecting the update, passed to
+ * update_ref_lock(). Can be REF_NODEREF, which means that
+ * symbolic references should not be followed.
+ *
+ * msg -- a message describing the change (for the reflog).
+ *
+ * err -- a strbuf for receiving a description of any error that
+ * might have occured.
+ *
+ * The functions make internal copies of refname and msg, so the
+ * caller retains ownership of these parameters.
+ *
+ * The functions return 0 on success and non-zero on failure. A
+ * failure means that the transaction as a whole has failed and needs
+ * to be rolled back.