--- a/views/Extractapp/TaggingText.php	Tue Apr 21 16:41:36 2015 +0200
+++ b/views/Extractapp/TaggingText.php	Thu Apr 23 14:58:27 2015 +0200
@@ -1,9 +1,34 @@
 <?php
+/*
+ * TaggingText.php
+ * This file is part of Extraction-interface.
+ *
+ * Extraction-interface 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.
+ *
+ * Extraction-interface 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 Extraction-interface.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
 /*! \file 
  * This is the view for TaggingText.
  * It shows the extraction-interface application itself.
- * It contains the tagging area and toolbox on the right side.
- *  
+ * The input data for this view come from models/extractapp.php which is handled by controllers/extractapp.php.
+ * Input data for example, are (1)text string (containing tags if there are any), 
+ * (2)taglist for the current topic, (3)book and section information, etc.
+ * The output data are passed to backend by controller to corresponding method in model/extractapp.php.
+ * Output data is the tagged text string.
+ * 
+ * The user interface contains tagging area on the left side, and toolbox on the right side.
+ * There are popup windows to assist the tagging task, for example RegEx-editors, tag-window, remove-tag-window, etc.
+ * 
 */
 
 // --- initialize config file and input text ---