--- a/README.md	Thu Jan 30 17:52:14 2014 +0100
+++ b/README.md	Fri Jan 31 16:08:50 2014 +0100
@@ -332,4 +332,12 @@
   +  last doctags: php app/console wikitag:load-fixtures -B 40001 /path/to/data.json
 
 The -B (index Begin) and -E (index End) works alson on the tags. Therefore you cans import tags also in slices.
+
+## Migration
+
+The wikitag folder contains a migration in DoctrineMigrations/Version20140129151724.php. If your wikitag is anterior to V00.14, you need to to do this migration.
+This migration takes every tag label and searches the REAL dbpedia uri associated to this label.
+Before, the dbpedia uri was manually generated by http://dbpedia.org/resource/ + english_label.
+Now we get the dbpedia uri by requesting http://LANG_CODE.dbpedia.org/sparql with the current label. 
+