Added ENVIRONMENT to reserved constants. Fixes #196
diff --git a/user_guide/general/reserved_names.html b/user_guide/general/reserved_names.html
index d1ee295..00bebff 100644
--- a/user_guide/general/reserved_names.html
+++ b/user_guide/general/reserved_names.html
@@ -90,6 +90,7 @@
 </ul>
 <h3>Constants</h3>
 <ul>
+	<li>ENVIRONMENT</li>
 	<li>EXT</li>
 	<li>FCPATH</li>
 	<li>SELF</li>