-element from your dataset. All values are repetable, so you always have to create
-array of values if you are creating new columns, even for single value.
+element from your dataset.
+
+If you want to create or update values, you will have to use $update hash to set
+new values.
+
+If you want to report something from your dataset (also called reduce in map/reduce
+terminology) you can use $out hash to store values which will be used to generate
+new dataset using $key and $value for column names.
+
+All values are repetable, but if you create just a scalar, magic(tm) inside MojoFacets
+will try to upgrade it to [ $scalar ] so you don't have to do it explicitly.
+
+Code examples are stored in public/code
+
+They use column1,column2.description.pl notatition so only snippets which have applicable
+column will be shown.