diff -r 13a41e435ea0 -r 878648aa663f src/relpipe-out-xml.cpp
--- a/src/relpipe-out-xml.cpp	Sun Sep 16 18:12:31 2018 +0200
+++ b/src/relpipe-out-xml.cpp	Thu Nov 29 22:30:12 2018 +0100
@@ -1,3 +1,20 @@
+/**
+ * Relational pipes
+ * Copyright © 2018 František Kučera (Frantovo.cz, GlobalCode.info)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
 #include <cstdlib>
 #include <unistd.h>
 #include <memory>