diff --git a/app/models/domain.rb b/app/models/domain.rb
index 6c7d0f0..edb0f48 100644
--- a/app/models/domain.rb
+++ b/app/models/domain.rb
@@ -8,9 +8,9 @@ class Domain < ActiveRecord::Base
   # validations
   #############
 
-  # <tt>name</tt> must be a sequence of word characters (a to z, plus 0 to 9,
-  # plus '_'). Letters must be lowercase
-  validates_format_of :name, :with => /^([a-z0-9_-]+\.)+[a-z0-9_-]+$/, :message => N_('%{fn} must be composed only of lowercase latters (a to z), numbers (0 to 9), "_" and "-"').fix_i18n
+  # <tt>name</tt> must be sequences of alphanumeric characters (a to z, 
+  # 0 to 9), plus '_' or '-', separated by dots. Letters must be lowercase.
+  validates_format_of :name, :with => /^([a-z0-9_-]+\.)+[a-z0-9_-]+$/, :message => N_('%{fn} must be composed of sequences of lowercase letters (a to z), numbers (0 to 9), "_" and "-", separated by dots.').fix_i18n
 
   # checks validations that could not be expressed using Rails' predefined
   # validations. In particular:
--
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