diff --git a/conf/license.php b/conf/license.php
index af8c77f794e1d76871fa4c67345e932a7ee35c3e..b97cb3cfd2b5a49ed1065e8fe05b3dbd21161271 100644
--- a/conf/license.php
+++ b/conf/license.php
@@ -29,12 +29,16 @@ $license['cc-by-sa'] = array(
     'name' => 'CC Attribution-Share Alike 3.0 Unported',
     'url'  => 'http://creativecommons.org/licenses/by-sa/3.0/',
 );
+$license['cc-zero'] = array(
+    'name' => 'CC0 1.0 Universal',
+    'url'  => 'http://creativecommons.org/publicdomain/zero/1.0/',
+);
 $license['publicdomain'] = array(
     'name' => 'Public Domain',
     'url'  => 'http://creativecommons.org/licenses/publicdomain/',
 );
 $license['gnufdl'] = array(
-    'name' => 'GNU Free Documentation License 1.2',
-    'url'  => 'http://www.gnu.org/licenses/fdl-1.2.html',
+    'name' => 'GNU Free Documentation License 1.3',
+    'url'  => 'http://www.gnu.org/licenses/fdl-1.3.html',
 );
 
diff --git a/lib/images/license/badge/cc-zero.png b/lib/images/license/badge/cc-zero.png
new file mode 100644
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diff --git a/lib/images/license/button/cc-by-nc-nd.png b/lib/images/license/button/cc-by-nc-nd.png
index b27ead2f68a9287280f207532682e73acd941ef7..072f8cda0ab220f98162dec5c705c44298d9aeee 100644
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diff --git a/lib/images/license/button/cc-by-nc-sa.png b/lib/images/license/button/cc-by-nc-sa.png
index 1c54f994df06341ae0d3f460eda0c55fa0f92801..ed028fed9d6154b10bf73872ea925a9603a352ae 100644
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diff --git a/lib/images/license/button/cc-by-nc.png b/lib/images/license/button/cc-by-nc.png
index 33c7b1fa411da0653be64c5f468116564fd3b8d0..54ebdfbd8b88229b0cb6da644bde68c83181d87e 100644
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diff --git a/lib/images/license/button/cc-by-nd.png b/lib/images/license/button/cc-by-nd.png
index 52073c043abb52d477a41f0f379cc703054ac9a3..35eca20cc9b00faea53cbfb39cbfe34076cd3dfd 100644
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diff --git a/lib/images/license/button/cc-by-sa.png b/lib/images/license/button/cc-by-sa.png
index 0b1880f91ec62252ff0829f87fa99811f7177282..c67509f1264e4b845b643e340cb39970e432c711 100644
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diff --git a/lib/images/license/button/cc-by.png b/lib/images/license/button/cc-by.png
index 99d8efd35451b5bf544c4fe0bba80688e5533559..ecd2abc73bd3d0bd46b806eb93351c017f15ab22 100644
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diff --git a/lib/images/license/button/cc-zero.png b/lib/images/license/button/cc-zero.png
new file mode 100644
index 0000000000000000000000000000000000000000..27d41346493e6cfc3f63975e8532853932336b3f
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diff --git a/lib/images/license/button/cc.png b/lib/images/license/button/cc.png
index adfa085bdb708d26d06c07f6b2ed78ec2458d8ed..f640586c9d8a9d4f65fb12d457bc64102dd7a028 100644
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