diff --git a/app/models/metadata_template.rb b/app/models/metadata_template.rb
index 3d3eeef..bf4ac18 100644
--- a/app/models/metadata_template.rb
+++ b/app/models/metadata_template.rb
@@ -178,7 +178,7 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
 
   def allowed_tags
     @allowed_tags ||= %w[strong em del u mark p h1 h2 h3 h4 h5 h6 ul ol li img iframe audio video div figure
-                         figcaption a small].freeze
+                         figcaption a sub sup small].freeze
   end
 
   # Decifra el valor